[Patch v2] spi: nxp-fspi: Add 1us delay to make controller ready for next transaction
Board gets reset when performing burst read/write operations. On the other hand, no such behaviour is observed on small size operations.
In Linux, readl_poll_timeout API already add delay of 1us which is skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported version of Linux driver and U-boot poll_timeout API lacks delay functionality, add 1us delay so as to make controller ready for other transactions.
Signed-off-by: Kuldeep Singh kuldeep.singh@nxp.com --- v1: Add comments above udelay(1) change.
drivers/spi/nxp_fspi.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/spi/nxp_fspi.c b/drivers/spi/nxp_fspi.c index 0e6c7be..1c6538c 100644 --- a/drivers/spi/nxp_fspi.c +++ b/drivers/spi/nxp_fspi.c @@ -757,6 +757,13 @@ static int nxp_fspi_exec_op(struct spi_slave *slave, FSPI_STS0_ARB_IDLE, 1, POLL_TOUT, true); WARN_ON(err);
+ /* + * Watchdog gets triggered for large read/write/erase since this + * delay is not present in this API(readl_poll_timeout), add + * this delay here. + */ + udelay(1); + nxp_fspi_prepare_lut(f, op); /* * If we have large chunks of data, we read them through the AHB bus
On Tue, Apr 21, 2020 at 11:57 AM Kuldeep Singh kuldeep.singh@nxp.com wrote:
Board gets reset when performing burst read/write operations. On the other hand, no such behaviour is observed on small size operations.
In Linux, readl_poll_timeout API already add delay of 1us which is skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported version of Linux driver and U-boot poll_timeout API lacks delay functionality, add 1us delay so as to make controller ready for other transactions.
Can you link me, where does Linux add this delay?
Jagan.
-----Original Message----- From: Jagan Teki jagan@amarulasolutions.com Sent: Tuesday, April 21, 2020 1:45 PM To: Kuldeep Singh kuldeep.singh@nxp.com Cc: U-Boot-Denx u-boot@lists.denx.de Subject: [EXT] Re: [Patch v2] spi: nxp-fspi: Add 1us delay to make controller ready for next transaction
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On Tue, Apr 21, 2020 at 11:57 AM Kuldeep Singh mailto:kuldeep.singh@nxp.com wrote:
Board gets reset when performing burst read/write operations. On the other hand, no such behaviour is observed on small size operations.
In Linux, readl_poll_timeout API already add delay of 1us which is skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported version of Linux driver and U-boot poll_timeout API lacks delay functionality, add 1us delay so as to make controller ready for other
transactions.
Can you link me, where does Linux add this delay?
Please see[1] for Linux nxp flexspi driver code. fspi_readl_poll_tout, line: 795
If you see implementation of " fspi_readl_poll_tout ", it further calls "readl_poll_timeout" which includes delay of 1us. And also please see the difference of "readl_poll_timeout" api implementation in uboot and Linux. This api adds delay in Linux but skips it in uboot.
Thanks Kuldeep [1] https://elixir.bootlin.com/linux/latest/source/drivers/spi/spi-nxp-fspi.c
On Tue, Apr 21, 2020 at 2:56 PM Kuldeep Singh kuldeep.singh@nxp.com wrote:
-----Original Message----- From: Jagan Teki jagan@amarulasolutions.com Sent: Tuesday, April 21, 2020 1:45 PM To: Kuldeep Singh kuldeep.singh@nxp.com Cc: U-Boot-Denx u-boot@lists.denx.de Subject: [EXT] Re: [Patch v2] spi: nxp-fspi: Add 1us delay to make controller ready for next transaction
Caution: EXT Email
On Tue, Apr 21, 2020 at 11:57 AM Kuldeep Singh mailto:kuldeep.singh@nxp.com wrote:
Board gets reset when performing burst read/write operations. On the other hand, no such behaviour is observed on small size operations.
In Linux, readl_poll_timeout API already add delay of 1us which is skipped in U-boot. Since, NXP Flexspi U-boot driver is a ported version of Linux driver and U-boot poll_timeout API lacks delay functionality, add 1us delay so as to make controller ready for other
transactions.
Can you link me, where does Linux add this delay?
Please see[1] for Linux nxp flexspi driver code. fspi_readl_poll_tout, line: 795
If you see implementation of " fspi_readl_poll_tout ", it further calls "readl_poll_timeout" which includes delay of 1us. And also please see the difference of "readl_poll_timeout" api implementation in uboot and Linux. This api adds delay in Linux but skips it in uboot.
Yes, it worked for myself also. so please use the new api which I have introduced on this series [2]
[2] https://patchwork.ozlabs.org/project/uboot/patch/20200425110354.12381-3-jaga...
If you see implementation of " fspi_readl_poll_tout ", it further calls
"readl_poll_timeout" which includes delay of 1us.
And also please see the difference of "readl_poll_timeout" api
implementation in uboot and Linux.
This api adds delay in Linux but skips it in uboot.
Yes, it worked for myself also. so please use the new api which I have introduced on this series [2]
Thanks Jagan for the new API. I will respin this patch.
-Kuldeep
participants (2)
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Jagan Teki -
Kuldeep Singh