On Wed, 28 Sep 2022 04:38:46 -0700, Jani Nikula wrote: > > On Mon, 19 Sep 2022, Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx> wrote: > > Register GT0_PERF_LIMIT_REASONS (0x1381a8) is available only for > > Gen11+. Therefore ensure perf_limit_reasons sysfs/debugfs files are created > > only for Gen11+. Otherwise on Gen < 5 accessing these files results in the > > following oops: > > > > <1> [88.829420] BUG: unable to handle page fault for address: ffffc90000bb81a8 > > <1> [88.829438] #PF: supervisor read access in kernel mode > > <1> [88.829447] #PF: error_code(0x0000) - not-present page > > > > Bspec: 20008 > > Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/6863 > > Fixes: fe5979665f64 ("drm/i915/debugfs: Add perf_limit_reasons in debugfs") > > Fixes: fa68bff7cf27 ("drm/i915/gt: Add sysfs throttle frequency interfaces") > > Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx> > Hi Jani, > Ashutosh, can you provide a backport of this i.e. commit 0d2d201095e9 > ("drm/i915: Perf_limit_reasons are only available for Gen11+") that > applies cleanly on drm-intel-fixes, please? I've sent the patch: https://patchwork.freedesktop.org/series/109196/ Not sure though if it is worth applying on drm-intel-fixes because of one conflict with drm-tip which will need to be resolved manually. On drm-intel-fixes the crash mentioned above will be seen only on Gen < 5 if someone manually cat's the sysfs. We had to fix on drm-tip because there was a CI failure with Gen3 debugfs but that code is not in drm-intel-fixes. Thanks. -- Ashutosh
