On Wed, 28 Sep 2022 11:35:18 -0700, Rodrigo Vivi wrote: > > On Wed, Sep 28, 2022 at 11:17:06AM -0700, Dixit, Ashutosh wrote: > > 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 Hi Rodrigo, > The conflict shouldn't be that bad to resolve, but since the patch deviates > from the original, the new commit message needs to highlight and explain > that this is a backport and the reasons of the difference and including the sha > of the already merged patch. Similar to the option 3 of the stable rules. [1]. I have improved the commit message and sent out a v2. Please take a look. Thanks. -- Ashutosh > Well, another option is to wait until this patch gets propagated to Linus master > and then send the backported version to the stable mailing list. But again, > with the proper rules of the option 3. [1] > > [1] - https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > > > 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. > > since it is sysfs it is probably a good protection to have anyway. > > > > > Thanks. > > -- > > Ashutosh
