Re: [PATCH v1 1/1] spi: Remove unneded check for orig_nents

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Wed, May 22, 2024 at 12:03:33PM +0200, Neil Armstrong wrote:
> On 15/05/2024 23:09, Nícolas F. R. A. Prado wrote:
> > On Tue, May 07, 2024 at 11:10:27PM +0300, Andy Shevchenko wrote:
> > > Both dma_unmap_sgtable() and sg_free_table() in spi_unmap_buf_attrs()
> > > have checks for orig_nents against 0. No need to duplicate this.
> > > All the same applies to other DMA mapping API calls.
> > > 
> > > Also note, there is no other user in the kernel that does this kind of
> > > checks.
> > > 
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > 
> > Hi,
> > 
> > this commit caused a regression which I reported here:
> > 
> > https://lore.kernel.org/all/d3679496-2e4e-4a7c-97ed-f193bd53af1d@notapiano
> > 
> > along with some thoughts on the cause and a possible solution, though I'm not
> > familiar with this code base at all and would really appreciate any feedback you
> > may have.
> 
> I also see the same regression on the SM8550 and SM8650 platforms,
> please CC linux-arm-msm@xxxxxxxxxxxxxxx and me for a potential fix to test on those platforms.

There is still no answer from IOMMU patch author. Do you have the same trace
due to IOMMU calls? Anyway, I guess it would be nice to see it.

Meanwhile, I have three changes I posted in the replies to the initial report,
can you combine them all and test? This will be a plan B (? or A, depending on
the culprit).

-- 
With Best Regards,
Andy Shevchenko