On Thu, Oct 07, 2021 at 07:19:29PM +0200, Sebastian Andrzej Siewior wrote: > On 2021-10-07 12:59:28 [-0400], Joe Korty wrote: > > Convert IRQ blocking in intel_breadcrumbs_park() to a local lock. > > > > Affects 5.10-rt and all later releases, up to and including when > > rt was merged into mainline. > > RT was merged into mainline? Nobody tells me anything anymore??? > > > This problem has been reported in two other linux-rt-users postings, > > > > [PREEMPT_RT] i915: fix PREEMPT_RT locking splats (Clark Williams) > > [linux-5.12.y-rt] drm/i915/gt: Fix a lockdep warning with interrupts enabled (Jun Miao) > > > > Neither of these submit the obvious solution, nor, > > AFAICT, has either yet been acted on. So I muddy the > > waters further by submitting this, a third fix. > > 5.12 is longer maintained. Could you please take the latest devel tree > for testing and participate in > https://lore.kernel.org/all/20211005150046.1000285-1-bigeasy@xxxxxxxxxxxxx/ > > If anything I would prefer those patches backported into v5.10 if it is > affected. Hi Sebastian, Please add my 'Tested-by' to the below patch. [linux-5.12.y-rt] drm/i915/gt: Fix a lockdep warning with interrupts enabled (Jun Miao) What was tested was a backport to 5.10-rt. One reject was encountered, trivially resolved. No other adjustments were made. My regression tests of last night all passed without any of the usual lockdep splats occuring. Prior to this, I could be assured of a large enough flood of splats to overwhelm the kernel log. My test stand is a Supermicro C7Z170-SQ. This is tthe only system I have on which I could trigger the problem. I could not find this patch in the 5.12-rt or the 5.15-rt tree, so I fetched a copy out of the linux-rt-users archives, and backported that. Tested-by: Joe Korty <joe.korty@xxxxxxxxxxxxxxxxx>
