From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Slaby Subject: Re: i915_driver_irq_handler: irq 42: nobody cared Date: Tue, 10 Apr 2012 10:52:06 +0200 Message-ID: <4F83F4B6.3090503@suse.cz> References: <4F717CE3.4040206@suse.cz> <4F717D80.9040207@suse.cz> <4F758400.3080907@suse.cz> <1333104359_155028@CP5-2952> <4F75A303.3030409@suse.cz> <1333110296_156038@CP5-2952> <4F7F60BF.9070500@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4F7F60BF.9070500@suse.cz> Sender: linux-kernel-owner@vger.kernel.org To: Jiri Slaby Cc: Chris Wilson , Keith Packard , dri-devel@lists.freedesktop.org, LKML , daniel@ffwll.ch, Jesse Barnes List-Id: dri-devel@lists.freedesktop.org On 04/06/2012 11:31 PM, Jiri Slaby wrote: > On 03/30/2012 02:24 PM, Chris Wilson wrote: >> On Fri, 30 Mar 2012 14:11:47 +0200, Jiri Slaby wrot= e: >>> On 03/30/2012 12:45 PM, Chris Wilson wrote: >>>> On Fri, 30 Mar 2012 11:59:28 +0200, Jiri Slaby wr= ote: >>>>> I don't know what to dump more, because iir is obviously zero too= =2E What >>>>> other sources of interrupts are on the (G33) chip? >>>> >>>> IIR is the master interrupt, with chained secondary interrupt stat= uses. >>>> If IIR is 0, the interrupt wasn't raised by the GPU. >>> >>> This does not make sense, the handler does something different. Eve= n if >>> IIR is 0, it still takes a look at pipe stats. >> >> That was introduced in 05eff845a28499762075d3a72e238a31f4d2407c to c= lose >> a race where the pipestat triggered an interrupt after we processed = the >> secondary registers and before reseting the primary. >> >> But the basic premise that we should only enter the interrupt handle= r >> with IIR!=3D0 holds (presuming non-shared interrupt lines such as MS= I). >=20 > Ok, this behavior is definitely new. I get several "nobody cared" abo= ut > this interrupt a week. This never used to happen. And something weird > emerges in /proc/interrupts when this happens: > 42: 1003292 1212890 PCI-MSI-edge =EF=BF=BDs=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD:0000:00:02.0 > instead of > 42: 1006715 1218472 PCI-MSI-edge i915@pci:0000:00:02.0 See the difference of drm_device->devname: Before: 20 34 32 3a 20 20 20 20 31 34 30 35 34 36 32 20 | 42: 1405462 | 20 20 20 31 37 32 38 33 30 32 20 20 20 50 43 49 | 1728302 PCI| 2d 4d 53 49 2d 65 64 67 65 20 20 20 20 20 20 69 |-MSI-edge i| 39 31 35 40 70 63 69 3a 30 30 30 30 3a 30 30 3a |915@pci:0000:00:| 30 32 2e 30 0a |02.0.| After: 20 34 32 3a 20 20 20 20 31 30 30 33 32 39 32 20 | 42: 1003292 | 20 20 20 31 32 31 32 38 39 30 20 20 20 50 43 49 | 1212890 PCI| 2d 4d 53 49 2d 65 64 67 65 20 20 20 20 20 20 ef |-MSI-edge .| bf bd 73 ef bf bd ef bf bd ef bf bd ef bf bd 3a |..s............:| 30 30 30 30 3a 30 30 3a 30 32 2e 30 0a |0000:00:02.0.| Any idea what "ef bf bd" pattern could be? And who *shifts* the "0000:00:02.0" string? thanks, --=20 js suse labs