On Mon, Oct 27, 2014 at 12:44 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > On Sun, Oct 26, 2014 at 11:31 AM, Alex Deucher <alexdeucher@xxxxxxxxx> wrote: >> On Mon, Oct 13, 2014 at 12:11 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >>> [+cc Alex, Christian, dri-devel] >>> >>> On Sat, Oct 11, 2014 at 1:37 PM, Shawn Starr <shawn.starr@xxxxxxxxxx> wrote: >>>> On September 11, 2014 04:26:21 PM Bjorn Helgaas wrote: >>>>> [+cc linux-pci] >>>>> >>>>> On Sat, Aug 2, 2014 at 10:02 AM, Shawn Starr <shawn.starr@xxxxxxxxxx> wrote: >>>>> > Hello devs, >>>>> > >>>>> > There are two issues I am encountering with the PCIe Hotplug driver on my >>>>> > Lenovo Laptop (W500). I note this goes back further than 3.15. >>>>> > >>>>> > It is noted here: >>>>> > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id= >>>>> > f244d8b623dae7a7bc695b0336f67729b95a9736 >>>>> > https://bugzilla.kernel.org/show_bug.cgi?id=79701 >>>>> > >>>>> > And my open bug here: >>>>> > https://bugzilla.kernel.org/show_bug.cgi?id=77261 >>>>> > >>>>> > 1) If I enable the device to use both the integrated and discrete GPU, >>>>> > pciehp will decide to force unload radeon because it puts itself into a >>>>> > power saving state, fails back to the Intel integrated GPU in this case >>>>> > unless I tell radeon.ko to runpm=0 (no power management, then pciehp wont >>>>> > touch it). >>>>> > >>>>> > 2) If the Radeon GPU resets and you use pci_reset=1 for kernel module >>>>> > option, pciehp decides to force unload radeon even though the GPU is >>>>> > trying to setup after failing. >>>>> > >>>>> > Kernel I am using right now: 3.16.0-0.rc7.git3.1.fc21.x86_64 (about to >>>>> > boot into snapshot kernel-core-3.16.0-0.rc7.git4.1.fc21.x86_64) >>>>> Hi Shawn, >>>>> >>>>> Thanks for the report and sorry that it got dropped. But I see you're >>>>> cc'd on https://bugzilla.kernel.org/show_bug.cgi?id=79701, so you've >>>>> probably seen the work there. If you can try out the patches I just >>>>> posted, that would be great. >>>>> >>>>> Bjorn >>>> >>>> Hi Bjorn, >>>> >>>> For #1) This is fixed in linux-next (tracking 3.18.0-0.rc0.git1.2.fc22.1.x86_64 >>>> nondebug kernel for Fedora). PCIe HotPlug no longer unloads radeon. For this >>>> bugzilla report we can close it. >>>> >>>> #2) This still has weird results however, radeon.hard_reset=1 is experimental >>>> and while it attempts to reset GPU, PCIe HotPlug seems to interact in this. >>>> >>>> This can be tested by adding to grub command line radeon.hard_reset=1. >>>> When X has started up, trigger a reset by cat >>>> /sys/kernel/debug/dri/#/radeon_gpu_reset. It will output 0, cat it again will >>>> show 1. >>>> >>>> Attempt to drag a window. The this will trigger a GPU reset, but fail to >>>> recover, its unknown if PCIe HotPlug is preventing a proper reset or not but >>>> there is pciehp calls in the stack trace. >>> >>> A PCIe device reset usually looks like a hotplug event because the >>> PCIe link goes down and comes back up. As far as the PCI core is >>> concerned, it can't tell the difference between (1) a simple reset >>> where the link bounces and (2) removal of one device followed by >>> addition of another. >>> >>> b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events >>> for a device") addressed this for some similar cases, but it looks >>> like we probably need some more calls to pci_ignore_hotplug() in the >>> radeon driver reset methods. >>> >>> Can you please open a bugzilla and attach the complete dmesg log, >>> including the GPU reset and recovery failure? >> >> Is there a way we could temporarily disable pci hotplug around a GPU reset? > > There is pci_ignore_hotplug(). Do you mean something more? Oh, I > guess you mean a way to disable, then *re*-enable hotplug. We can > easily add that if that would help. Exactly. I was thinking I could disable hotplug, do the gpu hard reset, then re-enable hotplug. Alex _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
