1696691 - If /proc/bus/pci is inaccessible, libpci aborts the process

Status: VERIFIED FIXED

(Core :: Graphics, defect, P3)

Description

[Andrew Osmond [:aosmond] (he/him)]

PCI detection is optional and should fail gracefully. This is failing on the PinePhone, probably other ARM targets. We should check to see if /proc/bus/pci is accessible before calling any libpci methods.

Comment 1

[Leonard Lausen]

This failure causes hardware acceleration to be disabled on a laptop with Qualcomm Snapdragon 7c (sc7180). Hardware acceleration in Chromium works fine.

Comment 2

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1696691 - Check that we can access /sys/bus/pci before loading libpci.

Comment 3

[Andrew Osmond [:aosmond] (he/him)]

Chrome has an explicit check for /sys/bus/pci, let's mirror it:

https://source.chromium.org/chromium/chromium/src/+/main:third_party/angle/src/gpu_info_util/SystemInfo_libpci.cpp;drc=ddce2fc4e67fd4500d29cbe5f4993b3fb8e4e2ba;l=64

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/44cb37057289
Check that we can access /sys/bus/pci before loading libpci. r=rmader

Comment 5

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/44cb37057289

Comment 6

[Andrew Osmond [:aosmond] (he/him)]

Can you confirm that it is fixed in nightly?

Comment 7

[Leonard Lausen]

Can you point me to the aarch64 nightly builds for Linux? I couldn't find any

Comment 8

[Andrew Osmond [:aosmond] (he/him)]

Huh, you raise a good point. There does not appear to be one. I manually kicked off a build for mozilla-central:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=6ef44ba37573120b0a528dfbe86a8db8cf79f293

It should finish in an hour or so.

Comment 9

[Andrew Osmond [:aosmond] (he/him)]

https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/C5tepXYxSD-2wvFh5dmZ_A/runs/0/artifacts/public/build/target.tar.bz2

Comment 10

[Leonard Lausen]

Attachment: about:support.txt

Comment 11

[Leonard Lausen]

Attachment: about-support.txt

Comment 12

[Leonard Lausen]

It works well. Thank you. Please see the relevant output from about:support below.

Please uplift this fix to 104.

Comment 13

[Andrew Osmond [:aosmond] (he/him)]

Comment on attachment 9288001 [details]
Bug 1696691 - Check that we can access /sys/bus/pci before loading libpci.

Beta/Release Uplift Approval Request

• User impact if declined: Hardware acceleration may be denied unnecessarily for ARM users
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): It just checks to see if we can access the PCI system paths before attempting to use libpci, which crashes our GL probe process if we cannot. Trivial well understood change.
• String changes made/needed:
• Is Android affected?: Yes

Comment 14

[Andrew Osmond [:aosmond] (he/him)]

Comment on attachment 9288001 [details]
Bug 1696691 - Check that we can access /sys/bus/pci before loading libpci.

Let's ride the trains instead, given issues like bug 1783053.

Comment 15

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:aosmond, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox104 to wontfix.

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