2018-07-13 19:35 GMT+09:00 Marek Vasut marex@denx.de:
On 07/13/2018 12:22 PM, Masahiro Yamada wrote:
2018-07-13 19:18 GMT+09:00 Marek Vasut marex@denx.de:
On 07/13/2018 12:09 PM, Masahiro Yamada wrote:
Hi Marek
2018-07-13 17:56 GMT+09:00 Marek Vasut marex@denx.de:
On 07/13/2018 10:23 AM, Masahiro Yamada wrote:
Hi Marek,
2018-07-13 16:59 GMT+09:00 Marek Vasut marex@denx.de: > On 07/13/2018 07:13 AM, Masahiro Yamada wrote: >> 2018-07-12 21:51 GMT+09:00 Marek Vasut marex@denx.de: >>> On 06/20/2018 09:14 AM, Masahiro Yamada wrote: >>>> Hi Marek, >>> >>> Hi! >>> >>>> 2018-06-20 13:43 GMT+09:00 Marek Vasut marex@denx.de: >>>>> On 06/19/2018 08:39 AM, Masahiro Yamada wrote: >>>>>> Hi Marek, >>>>> >>>>> Hi, >>>>> >>>>>> 2018-06-08 5:17 GMT+09:00 Marek Vasut marex@denx.de: >>>>>>> Replace the ad-hoc DMA cache management functions with common bouncebuf, >>>>>>> since those functions are not handling cases where unaligned buffer is >>>>>>> passed in, >>>>>> >>>>>> >>>>>> Were you hit by a problem, >>>>>> or just-in-case replacement? >>>>> >>>>> Yes, UBI triggers unaligned cache operations on my system (SoCFPGA). >>>>>> I thought I took care of the buffer alignment. >>>>>> >>>>>> The bounce buffer is allocated by kmalloc(): >>>>>> https://github.com/u-boot/u-boot/blob/v2018.05/drivers/mtd/nand/denali.c#L13... >>>>>> >>>>>> According to the lib/linux_compat.c implementation, >>>>>> it returns memory aligned with ARCH_DMA_MINALIGN. >>>>>> >>>>>> >>>>>> If the buffer is passed from the upper MTD layer, >>>>>> the NAND core also makes sure the enough alignment: >>>>>> https://github.com/u-boot/u-boot/blob/v2018.05/drivers/mtd/nand/denali.c#L12... >>>>>> >>>>>> This is how this driver works in Linux. >>>>>> >>>>>> I'd rather want to keep the current code >>>>>> unless this is a real problem, >>>>>> >>>>>> >>>>>> One possible clean-up is to move dma_(un)map_single to a common place. >>>>> Is there any chance you can try UBI on the denali nand on uniphier ? :) >>>> >>>> >>>> I tested the driver only for raw block devices. >>>> >>>> OK, I will test UBI on my platform. >>>> >>>> BTW, do you see the problem only in U-Boot? >>>> Is the denali driver in Linux working fine? >>> >>> Bump on this one ? >>> >> >> Sorry for delay. >> >> >> UBI is working for me without your patch. >> >> Not sure what is the difference. >> >> I will dig into it a little more, though. > > Verify that you're not seeing any unaligned cache flushes. I do.
Yeah, I am testing it now, but I never see 'Misaligned operation at range' when using UBI.
However, I found a simple way to trigger the warning in raw device access.
=> nand read 81000010 0 1000
NAND read: device 0 offset 0x0, size 0x1000 CACHE: Misaligned operation at range [81000010, 81001010] CACHE: Misaligned operation at range [81000010, 81001010] CACHE: Misaligned operation at range [81000010, 81001010] CACHE: Misaligned operation at range [81000010, 81001010] 4096 bytes read: OK
I can fix it with one liner.
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 6266c8a..f391727 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -1270,7 +1270,7 @@ int denali_init(struct denali_nand_info *denali) denali->dma_avail = 1;
if (denali->dma_avail) {
chip->buf_align = 16;
chip->buf_align = ARCH_DMA_MINALIGN; if (denali->caps & DENALI_CAP_DMA_64BIT) denali->setup_dma = denali_setup_dma64; elseI guess this will work for you too.
Doesn't that only apply if DMA is available ?
Of course. If you use PIO instead of DMA, you do not need to perform cache operation, right?
And anyway, I'd rather use common U-Boot code than have a custom implementation in a driver which we need to maintain and fix separately.
bounce_buffer_{start,stop} does malloc() and free() every time. This is not efficient.
struct nand_chip already contains page buffers, which guarantee alignment for DMA.
https://github.com/u-boot/u-boot/blob/v2018.07/include/linux/mtd/rawnand.h#L...
We can rely on the NAND framework for handling DMA-capable alignment.
Clearly that doesn't work, otherwise I won't need this bounce buffer patch ?
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 6266c8a..f391727 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -1270,7 +1270,7 @@ int denali_init(struct denali_nand_info *denali) denali->dma_avail = 1;
if (denali->dma_avail) {
chip->buf_align = 16;
chip->buf_align = ARCH_DMA_MINALIGN; if (denali->caps & DENALI_CAP_DMA_64BIT) denali->setup_dma = denali_setup_dma64; elseDid you try this? I do not see unaligned cache operation.
Nope, I'll have to assemble the hardware. But this only works if dma_avail, right ?
So, what are you worried about?