[U-Boot] [PATCH] spi: mxc: Fix data loss for non aligned write buffers.

Albert ARIBAUD
2013-10-16T12:05:36Z

Hi Jagan,

On Wed, 16 Oct 2013 16:20:17 +0530, Jagan Teki
<jagannadh.teki@gmail.com> wrote:

> Hi Amicalement,
>
> On Wed, Oct 16, 2013 at 1:05 PM, Albert ARIBAUD
> <albert.u.boot@aribaud.net> wrote:
> > Hi Jagan,
> >
> > On Wed, 16 Oct 2013 11:16:49 +0530, Jagan Teki
> > <jagannadh.teki@gmail.com> wrote:
> >
> >> Hi,
> >>
> >> On Tue, Oct 15, 2013 at 11:27 PM, Martin Fuzzey <mfuzzey@parkeon.com> wrote:
> >> > When writing buffers that are not 32 bit aligned data loss occurs.
> >> >
> >> > This can also occur when the total transfer size is not a multiple of 4 bytes
> >> > since the extra bytes are written first causing the rest to be unaligned.
> >> >
> >> > This can be seen by writing to SPI flash a 57 byte file containing 00 01 .. 38:
> >> >
> >> > U-Boot > dhcp data.bin
> >> > ...
> >> > Bytes transferred = 57 (39 hex)
> >> > U-Boot > md.b $loadaddr
> >> > 72000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................
> >> > 72000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................
> >> > 72000020: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./
> >> > 72000030: 30 31 32 33 34 35 36 37 38 ff ff ff ff ff ff ff 012345678.......
> >> > U-Boot > sf write $loadaddr 0 $filesize
> >> >
> >> > U-Boot > mw.b $loadaddr ff 100
> >> > U-Boot > sf read $loadaddr 0 100
> >> > U-Boot > md.b $loadaddr
> >> > 72000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................
> >> > 72000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................
> >> > 72000020: 20 21 22 23 24 29 2a 2b 2c 31 32 33 34 ff ff ff !"#$)*+,1234...
> >> > 72000030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> >> >
> >> > [bytes 25-28, 2d-30, 35-38 are missing]
> >> >
> >> > Activating debug in the write command gave:
> >> > spi_xchg_single: bitlen 256 dout 0x72000000 din 0x0
> >> > Sending SPI 0x10203
> >> > Sending SPI 0x4050607
> >> > Sending SPI 0x8090a0b
> >> > Sending SPI 0xc0d0e0f
> >> > Sending SPI 0x10111213
> >> > Sending SPI 0x14151617
> >> > Sending SPI 0x18191a1b
> >> > Sending SPI 0x1c1d1e1f
> >> > SPI Rx: 0xffffffff 0xffffffff
> >> > ...
> >> > SPI Rx: 0xffffffff 0xffffffff
> >> > spi_xchg_single: bitlen 200 dout 0x72000020 din 0x0
> >> > Sending SPI 0x20
> >> > Sending SPI 0x21222324
> >> > Sending SPI 0x292a2b2c <=== What happened to 25262728?
> >> > Sending SPI 0x31323334
> >> > Sending SPI 0xffffffff
> >> > ...
> >> > SF: program success 57 bytes @ 0x0
> >> Thanks for your log, for showing the exact issues.
> >
> > Agreed, but I think this log could go in a comment below the '---'
> > line, so that the commit message focuses on describing what the patch
> > does, rather than how it was found out necessary.
>
> I too thought the same, but the commit is already in master, any
> possibility to alter?

Er... Martin's patch is already in patchwork as 283794, but its state
is still "New" with no delegate, and I don't see it in any of the
repos I usually read, nor does it appear on u-boot-spi. Where do you
see it "in master" exactly?

Besides, it is less than 24 hours old; this is not enough time for
review, and therefore, it should not be accepted yet.

Amicalement,
--
Albert.