[PATCH] mtd: mxs_nand: default to legacy bch and rename to modern bch option
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Fixes: 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry") Signed-off-by: Sean Nyekjaer sean@geanix.com --- drivers/mtd/nand/raw/mxs_nand.c | 2 +- drivers/mtd/nand/raw/mxs_nand_dt.c | 2 +- include/mxs_nand.h | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/nand/raw/mxs_nand.c b/drivers/mtd/nand/raw/mxs_nand.c index e6bbfac4d6..49795e20d2 100644 --- a/drivers/mtd/nand/raw/mxs_nand.c +++ b/drivers/mtd/nand/raw/mxs_nand.c @@ -1119,7 +1119,7 @@ static int mxs_nand_set_geometry(struct mtd_info *mtd, struct bch_geometry *geo) }
if ((!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0) && - mtd->oobsize < 1024) || nand_info->legacy_bch_geometry) { + mtd->oobsize < 1024) || !nand_info->modern_bch_geometry) { dev_warn(mtd->dev, "use legacy bch geometry\n"); return mxs_nand_legacy_calc_ecc_layout(geo, mtd); } diff --git a/drivers/mtd/nand/raw/mxs_nand_dt.c b/drivers/mtd/nand/raw/mxs_nand_dt.c index 878796d555..bbb7396324 100644 --- a/drivers/mtd/nand/raw/mxs_nand_dt.c +++ b/drivers/mtd/nand/raw/mxs_nand_dt.c @@ -92,7 +92,7 @@ static int mxs_nand_dt_probe(struct udevice *dev)
info->use_minimum_ecc = dev_read_bool(dev, "fsl,use-minimum-ecc");
- info->legacy_bch_geometry = dev_read_bool(dev, "fsl,legacy-bch-geometry"); + info->modern_bch_geometry = dev_read_bool(dev, "fsl,modern-bch-geometry");
if (IS_ENABLED(CONFIG_CLK) && IS_ENABLED(CONFIG_IMX8)) { /* Assigned clock already set clock */ diff --git a/include/mxs_nand.h b/include/mxs_nand.h index c0cefaca90..7e254d6b31 100644 --- a/include/mxs_nand.h +++ b/include/mxs_nand.h @@ -43,8 +43,8 @@ struct mxs_nand_info { struct udevice *dev; unsigned int max_ecc_strength_supported; bool use_minimum_ecc; - /* legacy bch geometry flag */ - bool legacy_bch_geometry; + /* modern bch geometry flag */ + bool modern_bch_geometry; int cur_chip;
uint32_t cmd_queue_len;
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by default not the legacy bch setting, unless users enable it in DT file.
Fixes: 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry") Signed-off-by: Sean Nyekjaer sean@geanix.com
drivers/mtd/nand/raw/mxs_nand.c | 2 +- drivers/mtd/nand/raw/mxs_nand_dt.c | 2 +- include/mxs_nand.h | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/nand/raw/mxs_nand.c b/drivers/mtd/nand/raw/mxs_nand.c index e6bbfac4d6..49795e20d2 100644 --- a/drivers/mtd/nand/raw/mxs_nand.c +++ b/drivers/mtd/nand/raw/mxs_nand.c @@ -1119,7 +1119,7 @@ static int mxs_nand_set_geometry(struct mtd_info *mtd, struct bch_geometry *geo) }
if ((!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0) &&
mtd->oobsize < 1024) || nand_info->legacy_bch_geometry) {
mtd->oobsize < 1024) || !nand_info->modern_bch_geometry) { dev_warn(mtd->dev, "use legacy bch geometry\n"); return mxs_nand_legacy_calc_ecc_layout(geo, mtd); }diff --git a/drivers/mtd/nand/raw/mxs_nand_dt.c b/drivers/mtd/nand/raw/mxs_nand_dt.c index 878796d555..bbb7396324 100644 --- a/drivers/mtd/nand/raw/mxs_nand_dt.c +++ b/drivers/mtd/nand/raw/mxs_nand_dt.c @@ -92,7 +92,7 @@ static int mxs_nand_dt_probe(struct udevice *dev)
info->use_minimum_ecc = dev_read_bool(dev, "fsl,use-minimum-ecc");
info->legacy_bch_geometry = dev_read_bool(dev, "fsl,legacy-bch-geometry");
info->modern_bch_geometry = dev_read_bool(dev, "fsl,modern-bch-geometry"); if (IS_ENABLED(CONFIG_CLK) && IS_ENABLED(CONFIG_IMX8)) { /* Assigned clock already set clock */diff --git a/include/mxs_nand.h b/include/mxs_nand.h index c0cefaca90..7e254d6b31 100644 --- a/include/mxs_nand.h +++ b/include/mxs_nand.h @@ -43,8 +43,8 @@ struct mxs_nand_info { struct udevice *dev; unsigned int max_ecc_strength_supported; bool use_minimum_ecc;
/* legacy bch geometry flag */bool legacy_bch_geometry;
/* modern bch geometry flag */bool modern_bch_geometry; int cur_chip; uint32_t cmd_queue_len;-- 2.31.0
On 11/05/2021 04.49, han.xu wrote:
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by default not the legacy bch setting, unless users enable it in DT file.
Hi,
Adding, mtd-list and Miquel
With u-boot dtb: &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; compatible = "fsl,imx7d-gpmi-nand"; nand-on-flash-bbt; status = "okay"; };
With linux dtb (mainline 5.10): &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; nand-on-flash-bbt; status = "okay"; };
U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that commit it selects 8 bits. With legacy option it selects 18. Linux is selecting 18 bits ;) So now we have a mismatch.
I have been searching for the legacy option in the mainline kernel can't find it ;) Please show me where it is (is it in the NXP fork?)
/Sean
On 21/05/11 07:08AM, Sean Nyekjaer wrote:
Caution: EXT Email
On 11/05/2021 04.49, han.xu wrote:
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by default not the legacy bch setting, unless users enable it in DT file.
Hi,
Adding, mtd-list and Miquel
With u-boot dtb: &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; compatible = "fsl,imx7d-gpmi-nand"; nand-on-flash-bbt; status = "okay"; };
With linux dtb (mainline 5.10): &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; nand-on-flash-bbt; status = "okay"; };
U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that commit it selects 8 bits. With legacy option it selects 18. Linux is selecting 18 bits ;) So now we have a mismatch.
I have been searching for the legacy option in the mainline kernel can't find it ;) Please show me where it is (is it in the NXP fork?)
You are right, it's only fixed in NXP fork, with kernel driver modification. We prefer the current u-boot bch geometry, so I will send out a kernel patch to make them align.
/Sean
On 13/05/2021 22.02, han.xu wrote:
On 21/05/11 07:08AM, Sean Nyekjaer wrote:
Caution: EXT Email
On 11/05/2021 04.49, han.xu wrote:
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by default not the legacy bch setting, unless users enable it in DT file.
Hi,
Adding, mtd-list and Miquel
With u-boot dtb: &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; compatible = "fsl,imx7d-gpmi-nand"; nand-on-flash-bbt; status = "okay"; };
With linux dtb (mainline 5.10): &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; nand-on-flash-bbt; status = "okay"; };
U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that commit it selects 8 bits. With legacy option it selects 18. Linux is selecting 18 bits ;) So now we have a mismatch.
I have been searching for the legacy option in the mainline kernel can't find it ;) Please show me where it is (is it in the NXP fork?)
You are right, it's only fixed in NXP fork, with kernel driver modification. We prefer the current u-boot bch geometry, so I will send out a kernel patch to make them align.
Any progress on this?
I see your patch in: https://source.codeaurora.org/external/imx/linux-imx/commit/drivers/mtd/nand...
But I can't find the option for selecting legacy mode in the devicetree...
/Sean
Hi Stefano,
this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask.
This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel.
This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]).
There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default.
The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.
For the reasons above I would like to ask U-Boot maintainers to pick up this patch.
Thanks Frieder
[1] https://lists.denx.de/pipermail/u-boot/2022-March/477828.html [2] https://patchwork.ozlabs.org/project/linux-mtd/patch/20210522205136.19465-2-...
Am 20.05.21 um 11:09 schrieb Sean Nyekjaer:
On 13/05/2021 22.02, han.xu wrote:
On 21/05/11 07:08AM, Sean Nyekjaer wrote:
Caution: EXT Email
On 11/05/2021 04.49, han.xu wrote:
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by default not the legacy bch setting, unless users enable it in DT file.
Hi,
Adding, mtd-list and Miquel
With u-boot dtb: &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; compatible = "fsl,imx7d-gpmi-nand"; nand-on-flash-bbt; status = "okay"; };
With linux dtb (mainline 5.10): &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; nand-on-flash-bbt; status = "okay"; };
U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that commit it selects 8 bits. With legacy option it selects 18. Linux is selecting 18 bits ;) So now we have a mismatch.
I have been searching for the legacy option in the mainline kernel can't find it ;) Please show me where it is (is it in the NXP fork?)
You are right, it's only fixed in NXP fork, with kernel driver modification. We prefer the current u-boot bch geometry, so I will send out a kernel patch to make them align.
Any progress on this?
I see your patch in: https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.cod...
But I can't find the option for selecting legacy mode in the devicetree...
/Sean
On Thu, Mar 17, 2022 at 8:27 AM Frieder Schrempf < frieder.schrempf@kontron.de> wrote:
Hi Stefano,
this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask.
This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel.
This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]).
There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default.
The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.
Hi Frieder,
I am not in office this week. I will send another patch set to change in both kernel and u-boot to fix the compatible issue.
For the reasons above I would like to ask U-Boot maintainers to pick up this patch.
Thanks Frieder
[1] https://lists.denx.de/pipermail/u-boot/2022-March/477828.html [2]
https://patchwork.ozlabs.org/project/linux-mtd/patch/20210522205136.19465-2-...
Am 20.05.21 um 11:09 schrieb Sean Nyekjaer:
On 13/05/2021 22.02, han.xu wrote:
On 21/05/11 07:08AM, Sean Nyekjaer wrote:
Caution: EXT Email
On 11/05/2021 04.49, han.xu wrote:
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by
default
not the legacy bch setting, unless users enable it in DT file.
Hi,
Adding, mtd-list and Miquel
With u-boot dtb: &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; compatible = "fsl,imx7d-gpmi-nand"; nand-on-flash-bbt; status = "okay"; };
With linux dtb (mainline 5.10): &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; nand-on-flash-bbt; status = "okay"; };
U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that
commit it selects 8 bits.
With legacy option it selects 18. Linux is selecting 18 bits ;) So now we have a mismatch.
I have been searching for the legacy option in the mainline kernel
can't find it ;)
Please show me where it is (is it in the NXP fork?)
You are right, it's only fixed in NXP fork, with kernel driver
modification. We
prefer the current u-boot bch geometry, so I will send out a kernel
patch to
make them align.
Any progress on this?
I see your patch in:
https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.cod...
But I can't find the option for selecting legacy mode in the
devicetree...
/Sean
Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
Hi Han,
Am 17.03.22 um 14:33 schrieb Han Xu:
On Thu, Mar 17, 2022 at 8:27 AM Frieder Schrempf <frieder.schrempf@kontron.de mailto:frieder.schrempf@kontron.de> wrote:
Hi Stefano, this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask. This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel. This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]). There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default. The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.Hi Frieder,
I am not in office this week. I will send another patch set to change in both kernel and u-boot to fix the compatible issue.
You already claimed that months ago, but nothing happened:
I will send patches for both kernel and u-boot to use legacy bch scheme by default, and add some code to treat few MLC nand chips as corner cases.
Sean's U-Boot patch is effectively reverting the default behavior to use the "legacy" BCH scheme. So that's in line with what you want to do and you can base your work on top of this fix. But we should get the basic fix in regardless.
Even more so because switching the layout in U-Boot by using fsl,legacy-bch-geometry in the devicetree requires CONFIG_DM_MTD=y, which causes the bootloader size to increase by around 250 KiB in my case which might not be an option for some boards.
Thanks Frieder
Hi Ye,
Am 17.03.22 um 14:54 schrieb Frieder Schrempf:
Hi Han,
Am 17.03.22 um 14:33 schrieb Han Xu:
On Thu, Mar 17, 2022 at 8:27 AM Frieder Schrempf <frieder.schrempf@kontron.de mailto:frieder.schrempf@kontron.de> wrote:
Hi Stefano, this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask. This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel. This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]). There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default. The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.Hi Frieder,
I am not in office this week. I will send another patch set to change in both kernel and u-boot to fix the compatible issue.
You already claimed that months ago, but nothing happened:
I will send patches for both kernel and u-boot to use legacy bch scheme by default, and add some code to treat few MLC nand chips as corner cases.
Sean's U-Boot patch is effectively reverting the default behavior to use the "legacy" BCH scheme. So that's in line with what you want to do and you can base your work on top of this fix. But we should get the basic fix in regardless.
Even more so because switching the layout in U-Boot by using fsl,legacy-bch-geometry in the devicetree requires CONFIG_DM_MTD=y, which causes the bootloader size to increase by around 250 KiB in my case which might not be an option for some boards.
Ye's reply copied over to not break the thread:
The dt nand driver will check "fsl,legacy-bch-geometry" property to use legacy bch. If this can't work for you in case you don't use DM driver, I prefer adding a config to select the legacy bch not reverting the patch.
I think you miss my point. I don't really care about your preferences. But I do care about not introducing breaking changes. IMHO the "correct" way to introduce the new BCH layout would have been:
1. Introduce the new layout in Linux and U-Boot behind a feature-flag (e.g. DT property) 2. Make all upstream board configurations and DTs in Linux and U-Boot use the feature-flag. 3. Drop the flag and make the new BCH layout the default.
That way the change would be much more controlled and raise the awareness of board maintainers that are affected.
The current situation (layout changes applied in U-Boot without any questioning, layout changes in Linux rejected for good reasons) leaves everyone who uses the GPMI NAND on i.MX in a situation where they probably will see failures and need to spend some hours of debugging until they find out the reason is that someone carelessly introduced breaking changes.
And even with the procedure described above we break compatibility between old and new versions of U-Boot and Linux and create a dependency between the two which is what we should try to avoid wherever possible.
Frieder
On Mon, Mar 21, 2022 at 1:34 AM Frieder Schrempf frieder.schrempf@kontron.de wrote:
Hi Ye,
Am 17.03.22 um 14:54 schrieb Frieder Schrempf:
Hi Han,
Am 17.03.22 um 14:33 schrieb Han Xu:
On Thu, Mar 17, 2022 at 8:27 AM Frieder Schrempf <frieder.schrempf@kontron.de mailto:frieder.schrempf@kontron.de> wrote:
Hi Stefano, this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask. This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel. This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]). There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default. The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.Hi Frieder,
I am not in office this week. I will send another patch set to change in both kernel and u-boot to fix the compatible issue.
You already claimed that months ago, but nothing happened:
I will send patches for both kernel and u-boot to use legacy bch scheme by default, and add some code to treat few MLC nand chips as corner cases.
Sean's U-Boot patch is effectively reverting the default behavior to use the "legacy" BCH scheme. So that's in line with what you want to do and you can base your work on top of this fix. But we should get the basic fix in regardless.
Even more so because switching the layout in U-Boot by using fsl,legacy-bch-geometry in the devicetree requires CONFIG_DM_MTD=y, which causes the bootloader size to increase by around 250 KiB in my case which might not be an option for some boards.
Ye's reply copied over to not break the thread:
The dt nand driver will check "fsl,legacy-bch-geometry" property to use legacy bch. If this can't work for you in case you don't use DM driver, I prefer adding a config to select the legacy bch not reverting the patch.
I think you miss my point. I don't really care about your preferences. But I do care about not introducing breaking changes. IMHO the "correct" way to introduce the new BCH layout would have been:
- Introduce the new layout in Linux and U-Boot behind a feature-flag
(e.g. DT property) 2. Make all upstream board configurations and DTs in Linux and U-Boot use the feature-flag. 3. Drop the flag and make the new BCH layout the default.
That way the change would be much more controlled and raise the awareness of board maintainers that are affected.
The current situation (layout changes applied in U-Boot without any questioning, layout changes in Linux rejected for good reasons) leaves everyone who uses the GPMI NAND on i.MX in a situation where they probably will see failures and need to spend some hours of debugging until they find out the reason is that someone carelessly introduced breaking changes.
And even with the procedure described above we break compatibility between old and new versions of U-Boot and Linux and create a dependency between the two which is what we should try to avoid wherever possible.
Frieder
Frieder,
I agree that we need to get this fixed ASAP. Because of this IMX GPMI NAND UBI has been broken since v2020.07 (6 releases ago!) and it would be really nice to get this fixed in v2022.01 which releases in a couple of weeks. I'm surprised neither of us noticed this problem but likely we've both been so busy trying to keep up with forced DM migrations we haven't fully tested the 'little things' like booting to an actual OS. I know the boards I support using IMX GPMI NAND UBI are still using a 2017 U-Boot where quite honestly everything worked fine so there hasn't been a reason to push people to something new.
That said, applying this patch does 'not' fix things for my boards. For my boards mxs_nand_set_geometry is called with: oobsize=224 ecc_str_ds=0 ecc_step_ds=0 modern=0
and I still get ecc errors when mounting a UBI that worked fine with a v2020.04 U-Boot: Ventana > ubi part rootfs && ubifsmount ubi0:boot && ubifsls && ubifsumount ubi0: attaching mtd3 ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 1:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 2:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 4096 bytes from PEB 2:4096, read 4096 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 3:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 4096 bytes from PEB 3:4096, read 4096 bytes
The original offending commit 616f03dabacb ("mtd: gpmi: change the BCH layout setting for large oob NAND") no longer reverts and I haven't dug in to find out what I can do about that but i'm a little concerned I get different results than you do regarding the patch from this thread.
Thank you for pursuing this issue!
Best Regards,
Tim
Best Regards,
On Mon, Mar 21, 2022 at 12:42 PM Tim Harvey tharvey@gateworks.com wrote:
On Mon, Mar 21, 2022 at 1:34 AM Frieder Schrempf frieder.schrempf@kontron.de wrote:
Hi Ye,
Am 17.03.22 um 14:54 schrieb Frieder Schrempf:
Hi Han,
Am 17.03.22 um 14:33 schrieb Han Xu:
On Thu, Mar 17, 2022 at 8:27 AM Frieder Schrempf <frieder.schrempf@kontron.de mailto:frieder.schrempf@kontron.de> wrote:
Hi Stefano, this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask. This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel. This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]). There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default. The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.Hi Frieder,
I am not in office this week. I will send another patch set to change in both kernel and u-boot to fix the compatible issue.
You already claimed that months ago, but nothing happened:
I will send patches for both kernel and u-boot to use legacy bch scheme by default, and add some code to treat few MLC nand chips as corner cases.
Sean's U-Boot patch is effectively reverting the default behavior to use the "legacy" BCH scheme. So that's in line with what you want to do and you can base your work on top of this fix. But we should get the basic fix in regardless.
Even more so because switching the layout in U-Boot by using fsl,legacy-bch-geometry in the devicetree requires CONFIG_DM_MTD=y, which causes the bootloader size to increase by around 250 KiB in my case which might not be an option for some boards.
Ye's reply copied over to not break the thread:
The dt nand driver will check "fsl,legacy-bch-geometry" property to use legacy bch. If this can't work for you in case you don't use DM driver, I prefer adding a config to select the legacy bch not reverting the patch.
I think you miss my point. I don't really care about your preferences. But I do care about not introducing breaking changes. IMHO the "correct" way to introduce the new BCH layout would have been:
- Introduce the new layout in Linux and U-Boot behind a feature-flag
(e.g. DT property) 2. Make all upstream board configurations and DTs in Linux and U-Boot use the feature-flag. 3. Drop the flag and make the new BCH layout the default.
That way the change would be much more controlled and raise the awareness of board maintainers that are affected.
The current situation (layout changes applied in U-Boot without any questioning, layout changes in Linux rejected for good reasons) leaves everyone who uses the GPMI NAND on i.MX in a situation where they probably will see failures and need to spend some hours of debugging until they find out the reason is that someone carelessly introduced breaking changes.
And even with the procedure described above we break compatibility between old and new versions of U-Boot and Linux and create a dependency between the two which is what we should try to avoid wherever possible.
Frieder
Frieder,
I agree that we need to get this fixed ASAP. Because of this IMX GPMI NAND UBI has been broken since v2020.07 (6 releases ago!) and it would be really nice to get this fixed in v2022.01 which releases in a couple of weeks. I'm surprised neither of us noticed this problem but likely we've both been so busy trying to keep up with forced DM migrations we haven't fully tested the 'little things' like booting to an actual OS. I know the boards I support using IMX GPMI NAND UBI are still using a 2017 U-Boot where quite honestly everything worked fine so there hasn't been a reason to push people to something new.
That said, applying this patch does 'not' fix things for my boards. For my boards mxs_nand_set_geometry is called with: oobsize=224 ecc_str_ds=0 ecc_step_ds=0 modern=0
and I still get ecc errors when mounting a UBI that worked fine with a v2020.04 U-Boot: Ventana > ubi part rootfs && ubifsmount ubi0:boot && ubifsls && ubifsumount ubi0: attaching mtd3 ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 1:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 2:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 4096 bytes from PEB 2:4096, read 4096 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 3:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 4096 bytes from PEB 3:4096, read 4096 bytes
The original offending commit 616f03dabacb ("mtd: gpmi: change the BCH layout setting for large oob NAND") no longer reverts and I haven't dug in to find out what I can do about that but i'm a little concerned I get different results than you do regarding the patch from this thread.
Thank you for pursuing this issue!
It looks like for my board this patch on top of commit 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry") does resolve the issue however on top of current 2022.04-rc4 there seems to be a new problem for me.
Adding some debugging I find that I used to see the following: mxs_nand_set_geometry legacy_bch_geometry=1 ecc_strength_ds=0 max_ecc_strength_supported=40 mxs_nand_legacy_calc_ecc_layout oobsize=224 ecc_chunk_count=8 ecc_chunk0_size=512 ecc_chunkn_size=512 ecc_strength=16
But now with this patch on top of 2022.04-rc4 I get: mxs_nand_set_geometry legacy_bch_geometry=1 ecc_strength_ds=0 max_ecc_strength_supported=40 mxs_nand_legacy_calc_ecc_layout oobsize=128 ecc_chunk_count=8 ecc_chunk0_size=512 ecc_chunkn_size=512 ecc_strength=8 ^^^ oobsize is wrong causing the wrong ecc strength (8 instead of the correct 16)
I'm not sure yet what happened between 51cdf83eea and now that causes oobsize to be wrong for my device.
Frieder, are you really able to run ok on 2022.04-rc4 with legacy mode selected?
Best Regards,
Tim
On Tue, Mar 22, 2022 at 10:13 AM Tim Harvey tharvey@gateworks.com wrote:
On Mon, Mar 21, 2022 at 12:42 PM Tim Harvey tharvey@gateworks.com wrote:
On Mon, Mar 21, 2022 at 1:34 AM Frieder Schrempf frieder.schrempf@kontron.de wrote:
Hi Ye,
Am 17.03.22 um 14:54 schrieb Frieder Schrempf:
Hi Han,
Am 17.03.22 um 14:33 schrieb Han Xu:
On Thu, Mar 17, 2022 at 8:27 AM Frieder Schrempf <frieder.schrempf@kontron.de mailto:frieder.schrempf@kontron.de> wrote:
Hi Stefano, this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask. This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel. This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]). There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default. The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.Hi Frieder,
I am not in office this week. I will send another patch set to change in both kernel and u-boot to fix the compatible issue.
You already claimed that months ago, but nothing happened:
I will send patches for both kernel and u-boot to use legacy bch scheme by default, and add some code to treat few MLC nand chips as corner cases.
Sean's U-Boot patch is effectively reverting the default behavior to use the "legacy" BCH scheme. So that's in line with what you want to do and you can base your work on top of this fix. But we should get the basic fix in regardless.
Even more so because switching the layout in U-Boot by using fsl,legacy-bch-geometry in the devicetree requires CONFIG_DM_MTD=y, which causes the bootloader size to increase by around 250 KiB in my case which might not be an option for some boards.
Ye's reply copied over to not break the thread:
The dt nand driver will check "fsl,legacy-bch-geometry" property to use legacy bch. If this can't work for you in case you don't use DM driver, I prefer adding a config to select the legacy bch not reverting the patch.
I think you miss my point. I don't really care about your preferences. But I do care about not introducing breaking changes. IMHO the "correct" way to introduce the new BCH layout would have been:
- Introduce the new layout in Linux and U-Boot behind a feature-flag
(e.g. DT property) 2. Make all upstream board configurations and DTs in Linux and U-Boot use the feature-flag. 3. Drop the flag and make the new BCH layout the default.
That way the change would be much more controlled and raise the awareness of board maintainers that are affected.
The current situation (layout changes applied in U-Boot without any questioning, layout changes in Linux rejected for good reasons) leaves everyone who uses the GPMI NAND on i.MX in a situation where they probably will see failures and need to spend some hours of debugging until they find out the reason is that someone carelessly introduced breaking changes.
And even with the procedure described above we break compatibility between old and new versions of U-Boot and Linux and create a dependency between the two which is what we should try to avoid wherever possible.
Frieder
Frieder,
I agree that we need to get this fixed ASAP. Because of this IMX GPMI NAND UBI has been broken since v2020.07 (6 releases ago!) and it would be really nice to get this fixed in v2022.01 which releases in a couple of weeks. I'm surprised neither of us noticed this problem but likely we've both been so busy trying to keep up with forced DM migrations we haven't fully tested the 'little things' like booting to an actual OS. I know the boards I support using IMX GPMI NAND UBI are still using a 2017 U-Boot where quite honestly everything worked fine so there hasn't been a reason to push people to something new.
That said, applying this patch does 'not' fix things for my boards. For my boards mxs_nand_set_geometry is called with: oobsize=224 ecc_str_ds=0 ecc_step_ds=0 modern=0
and I still get ecc errors when mounting a UBI that worked fine with a v2020.04 U-Boot: Ventana > ubi part rootfs && ubifsmount ubi0:boot && ubifsls && ubifsumount ubi0: attaching mtd3 ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 1:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 2:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 4096 bytes from PEB 2:4096, read 4096 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 3:0, read 64 bytes ubi0 error: ubi_io_read: error -74 (ECC error) while reading 4096 bytes from PEB 3:4096, read 4096 bytes
The original offending commit 616f03dabacb ("mtd: gpmi: change the BCH layout setting for large oob NAND") no longer reverts and I haven't dug in to find out what I can do about that but i'm a little concerned I get different results than you do regarding the patch from this thread.
Thank you for pursuing this issue!
It looks like for my board this patch on top of commit 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry") does resolve the issue however on top of current 2022.04-rc4 there seems to be a new problem for me.
Adding some debugging I find that I used to see the following: mxs_nand_set_geometry legacy_bch_geometry=1 ecc_strength_ds=0 max_ecc_strength_supported=40 mxs_nand_legacy_calc_ecc_layout oobsize=224 ecc_chunk_count=8 ecc_chunk0_size=512 ecc_chunkn_size=512 ecc_strength=16
But now with this patch on top of 2022.04-rc4 I get: mxs_nand_set_geometry legacy_bch_geometry=1 ecc_strength_ds=0 max_ecc_strength_supported=40 mxs_nand_legacy_calc_ecc_layout oobsize=128 ecc_chunk_count=8 ecc_chunk0_size=512 ecc_chunkn_size=512 ecc_strength=8 ^^^ oobsize is wrong causing the wrong ecc strength (8 instead of the correct 16)
I'm not sure yet what happened between 51cdf83eea and now that causes oobsize to be wrong for my device.
Frieder, are you really able to run ok on 2022.04-rc4 with legacy mode selected?
I discovered my issue regarding the wrong oobsize. When I converted to DM_MTD I removed CONFIG_SYS_NAND_ONFI_DETECTION which was needed.
With that fixed, Sean's patch here resolves the issue and puts me in sync with your findings.
I will take a look at Han's latest patch and respond to that thread.
Best Regards,
Tim
Hi Frieder,
sorry for late answer. On 17.03.22 14:24, Frieder Schrempf wrote:
Hi Stefano,
this old patch was delegated to you in patchwork. If you're not the correct maintainer to address, please let me know. As the NAND layer seems to be unmaintained at the moment, I'm not sure whom to ask.
I am not the maintainer, but I picked up also in the past patches for NAND else they could not be merged. I will do this time, too.
Han has sent a patch yesterday to align u-boot and kernel, and it is okay if it is assigned to me, I will then merge it. I see from Sean he can test on thursday.
Regards, Stefano
This patch fixes a regression that was introduced by 616f03dabacb (" mtd: gpmi: change the BCH layout setting for large oob NAND") which alters the BCH layout in a way that doesn't match with the implementation in the Linux kernel.
This causes failures when loading an UBI image in U-Boot that was flashed by Linux or vice versa (see [1]).
There has been an approach to fix this through an optional devicetree property in 51cdf83eea ("mtd: gpmi: provide the option to use legacy bch geometry"), but this is not acceptable. The "legacy" BCH layout compatible with Linux should be used by default.
The approach to upstream the "new" layout to the kernel [2] seems to be stalled and even if it would succeed, it would break systems that use an old U-Boot and a new kernel, which is again not really acceptable in my opinion.
For the reasons above I would like to ask U-Boot maintainers to pick up this patch.
Thanks Frieder
[1] https://lists.denx.de/pipermail/u-boot/2022-March/477828.html [2] https://patchwork.ozlabs.org/project/linux-mtd/patch/20210522205136.19465-2-...
Am 20.05.21 um 11:09 schrieb Sean Nyekjaer:
On 13/05/2021 22.02, han.xu wrote:
On 21/05/11 07:08AM, Sean Nyekjaer wrote:
Caution: EXT Email
On 11/05/2021 04.49, han.xu wrote:
On 21/05/10 12:00PM, Sean Nyekjaer wrote:
Caution: EXT Email
Linux kernel defaults to use legacy bch setting, this was creating a mismatch between U-boot and Linux default settings.
Kernel uses the NAND chip specified minimum ecc strength and steps by default not the legacy bch setting, unless users enable it in DT file.
Hi,
Adding, mtd-list and Miquel
With u-boot dtb: &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; compatible = "fsl,imx7d-gpmi-nand"; nand-on-flash-bbt; status = "okay"; };
With linux dtb (mainline 5.10): &gpmi { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpmi_nand1>; nand-on-flash-bbt; status = "okay"; };
U-boot prior to commit 51cdf83eea selected 18 bit ECC, after that commit it selects 8 bits. With legacy option it selects 18. Linux is selecting 18 bits ;) So now we have a mismatch.
I have been searching for the legacy option in the mainline kernel can't find it ;) Please show me where it is (is it in the NXP fork?)
You are right, it's only fixed in NXP fork, with kernel driver modification. We prefer the current u-boot bch geometry, so I will send out a kernel patch to make them align.
Any progress on this?
I see your patch in: https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.cod...
But I can't find the option for selecting legacy mode in the devicetree...
/Sean
participants (6)
-
Frieder Schrempf -
Han Xu -
han.xu -
Sean Nyekjaer -
Stefano Babic -
Tim Harvey