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? Alex _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
