<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - amdgpu 0000:07:00.0: swiotlb buffer is full (sz: 2097152 bytes)" href="https://bugs.freedesktop.org/show_bug.cgi?id=104082#c40">Comment # 40</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - amdgpu 0000:07:00.0: swiotlb buffer is full (sz: 2097152 bytes)" href="https://bugs.freedesktop.org/show_bug.cgi?id=104082">bug 104082</a> from <a class="email" href="mailto:jdelvare@suse.de" title="Jean Delvare <jdelvare@suse.de>"> Jean Delvare</a> <pre>I believe there are 2 incarnations of this bug, with the same symptoms but different root causes. The first bug is affecting kernels v4.14 and v4.15, it is caused by 2 MB allocations failing too verbosely when in fact 4 kB allocations worked just fine as a fallback. That one is fixed in v4.16 by: commit d0bc0c2a31c95002d37c3cc511ffdcab851b3256 Author: Christian König Date: Thu Jan 4 14:24:19 2018 +0100 swiotlb: suppress warning when __GFP_NOWARN is set However kernel v4.16 also includes the following commit: commit 0176adb004065d6815a8e67946752df4cd947c5b Author: Christoph Hellwig Date: Tue Jan 9 22:15:30 2018 +0100 swiotlb: refactor coherent buffer allocation which contains a bug producing exactly the same backtraces. That bug is caused by an improper check of the result of dma_coherent_ok(), which was fixed 10 days ago with: commit 9e7f06c8beee304ee21b791653fefcd713f48b9a Author: Takashi Iwai Date: Tue Apr 10 19:05:13 2018 +0200 swiotlb: fix unexpected swiotlb_alloc_coherent failures I backported this fix on top of v4.16.3 and the backtraces are gone. The commit was tagged for stable inclusion so I expect it to be included in v4.16.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>