Re: spi: imx: Increase imx51 ecspi burst length fails on imx6dl and imx8mm

["Linux regression tracking (Thorsten Leemhuis)" <regressions@xxxxxxxxxxxxx>]

[CCing people that worked on the relevant commits as well as the
regression list, as it should be in the loop for regressions:
https://docs.kernel.org/admin-guide/reporting-regressions.html]

On 18.11.23 15:25, linux@xxxxxxxxx wrote:
> After upgrade from kernel 6.5.11 to 6.6.1 the spi-devices on my hw 
> colibri-imx6dl and verdin-imx8mm are not working anymore (TPM2 and SPI-SRAM).
> 
> Analyzing the problem showed that the 2 commits introduced the problem:
> 
> spi: Increase imx51 ecspi burst length based on transfer length
> 15a6af94a2779d5dfb42ee4bfac858ea8e964a3f
> 
> spi: imx: Take in account bits per word instead of assuming 8-bits
> 5f66db08cbd3ca471c66bacb0282902c79db9274
> 
> Reverting the commits solved the problem.
> 
> The analyse with the logic-analyser showed a wrong number of transmitted  
> bytes and wrong data.
> When I try to send 127 Byte with a incrementing pattern (0x01,0x02,0x03,..),
> 504 Bytes are sent (0x00,0x00,0x01 0x00,0x00,0x00,0x02, 0x00,0x00,0x00,0x03).
> We tested with different sizes and patterns, all are not ok.
> While analysing the configuration and code I was not able to see any obvious
> mistake.
> 
> Has someone else discovered such misbehaviour or has any idea what is wrong?
> Best Regards

Thx for the report!

[TLDR: I'm adding this report to the list of tracked Linux kernel
regressions; the text you find below is based on a few templates
paragraphs you might have encountered already in similar form.
See link in footer if these mails annoy you.]

To ensure the issue doesn't fall through the cracks unnoticed, I'm
adding it to regzbot, the Linux kernel regression tracking bot:

#regzbot ^introduced 15a6af94a27
#regzbot title spi: spi-devices on colibri-imx6dl and verdin-imx8mm are
not working anymore
#regzbot ignore-activity

This isn't a regression? This issue or a fix for it are already
discussed somewhere else? It was fixed already? You want to clarify when
the regression started to happen? Or point out I got the title or
something else totally wrong? Then just reply and tell me -- ideally
while also telling regzbot about it, as explained by the page listed in
the footer of this mail.

Developers: When fixing the issue, remember to add 'Link:' tags pointing
to the report (the parent of this mail). See page linked in footer for
details.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
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