Re: i2c-designware: NULL ptr at RIP: 0010:regmap_read+0x12/0x70

[Kim Phillips <kim.phillips@amd.com>]

Hi,

On 1/9/24 4:11 AM, Jarkko Nikula wrote> On 1/9/24 09:56, V, Narasimhan wrote:
>>   * Looks like the issue is with this below commit:
>>   * i2c: designware: Fix lock probe call order in dw_i2c_plat_probe()
>>
> Hmm... This makes me even more confused since your device AMDI0010 should not even use the access semaphore.
> 
> So linux-next works if you run a commit before it or revert these three patches? (commit 2f571a725434 ("i2c: designware: Fix lock probe call order in dw_i2c_plat_probe()") doesn't revert without reverting two other related commits after it)
> 
> git show f9b51f600217b38f46ea39d6aa445e594bf3eb30 |patch -p1 -R
> git show b8034c7d28a988be82efbf4d65faa847334811f7 |patch -p1 -R
> git show 2f571a72543463ef07dc3ac61e7b703b9ad997f9 |patch -p1 -R

Narasimhan is right, if I check out, build and boot this commit:

       2f571a725434 i2c: designware: Fix lock probe call order in dw_i2c_plat_probe()

I get the same stacktrace on the serial console.

If I try the previous commit (174a0c565cea "efi/loongarch: Directly position the loaded image file"),
the system boots fine.

The same thing happens with the three reversions above:
next-20240110 gets the stacktrace, but with the three
reversions, it doesn't.

Is your parallel post probe runtime suspending time window
theory no longer applicable?  These AMD EPYC systems have a
lot more cores than their client equivalents, and AMD power
management code has had a lot of improvements lately.

Thanks,

Kim