https://bugzilla.kernel.org/show_bug.cgi?id=73901 --- Comment #9 from Pali Rohár <pali.rohar@xxxxxxxxx> --- I looked into radeon_atpx_handler.c code and I found reason why radeon kernel driver does not detect ATPX... First here is lspci output: 00:02.0 VGA compatible controller [0300]: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) 01:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Sun XT [Radeon HD 8670A/8670M/8690M] [1002:6660] Second here is relevant code of function radeon_atpx_detect(void) from file radeon_atpx_handler.c int vga_count = 0; while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) { vga_count++; has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true); } if (has_atpx && vga_count == 2) { ... ATPX was detected ... } And some defines (from pci_ids.h): #define PCI_CLASS_DISPLAY_VGA 0x0300 #define PCI_CLASS_DISPLAY_OTHER 0x0380 Because my Radeon card has pci class 0380 and not 0300 it is not checked for ATPX in while loop and so vgaswitcheroo is not enabled. I created this quick & dirty patch and after that runpm=1 working without any crash. --- radeon_atpx_handler.c.orig 2014-04-14 17:36:36.583744668 +0200 +++ radeon_atpx_handler.c 2014-04-14 23:50:53.354492060 +0200 @@ -528,6 +528,12 @@ static bool radeon_atpx_detect(void) has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true); } + while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) { + vga_count++; + + has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true); + } + if (has_atpx && vga_count == 2) { acpi_get_name(radeon_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer); printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n", Now also vgaswitcheroo debugfs file appeared: $ sudo cat /sys/kernel/debug/vgaswitcheroo/switch 0:IGD:+:Pwr:0000:00:02.0 1:DIS: :DynPwr:0000:01:00.0 Alex, I think that now you have everything needed for implementing proper fix for this bug. -- You are receiving this mail because: You are watching the assignee of the bug. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
