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