On 29.05.24 16:36, Linux regression tracking (Thorsten Leemhuis) wrote:

[CCing the regression list, as it should be in the loop for regressions:
https://docs.kernel.org/admin-guide/reporting-regressions.html]

On 20.05.24 17:15, Christoph Hellwig wrote:

quoted

Adding ben and the linuxppc list.

Hmm, no reply and no other progress to get this resolved afaics. So lets
bring Michael into the mix, he might be able to help out.

BTW TWIMC: a PowerMac G5 user user reported similar symptoms here
recently: https://bugzilla.kernel.org/show_bug.cgi?id=218858

And yet another report with similar symptoms, this time with a
"PowerMac7,2 PPC970 0x390202 PowerMac":
https://bugzilla.kernel.org/show_bug.cgi?id=218905

Ciao, Thorsten

quoted

Context: pata_macio initialization now fails as we enforce that the
segment size is set properly.

On Wed, May 15, 2024 at 04:52:29PM -0700, Guenter Roeck wrote:

quoted

pata_macio_common_init() Calling ata_host_activate() with limit 65280
...
max_segment_size is 65280; PAGE_SIZE is 65536; BLK_MAX_SEGMENT_SIZE is 65536
WARNING: CPU: 0 PID: 12 at block/blk-settings.c:202 blk_validate_limits+0x2d4/0x364
...

This is with PPC_BOOK3S_64 which selects a default page size of 64k.

Yeah.  Did you actually manage to use pata macio previously?  Or is
it just used because it's part of the pmac default config?

quoted

Looking at the old code, I think it did what you suggested above,

quoted

but assuming that the driver requested a lower limit on purpose that
may not be the best solution.

quoted

Never mind, though - I updated my test configuration to explicitly
configure the page size to 4k to work around the problem. With that,
please consider this report a note in case someone hits the problem
on a real system (and sorry for the noise).

Yes, the idea behind this change was to catch such errors.  So far
most errors have been drivers setting lower limits than what the
hardware can actually handle, but I'd love to track this down.

If the hardware can't actually handle the lower limit we should
probably just fail the probe gracefully with a well comment if
statement instead.