Re: [PATCH v15 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

On Thu, Jun 24, 2021 at 11:55:20PM +0800, Claire Chang wrote:

Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and
use it to determine whether to bounce the data or not. This will be
useful later to allow for different pools.

Signed-off-by: Claire Chang <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

This patch as commit af452ec1b1a3 ("swiotlb: Use is_swiotlb_force_bounce
for swiotlb data bouncing") causes my Ryzen 3 4300G system to fail to
get to an X session consistently (although not every single time),
presumably due to a crash in the AMDGPU driver that I see in dmesg.

I have attached logs at af452ec1b1a3 and f127c9556a8e and I am happy
to provide any further information, debug, or test patches as necessary.

Cheers,
Nathan