Just tried it and the system didn't freeze. However it will freeze after some time (few minutes while working). Seams to be pci_read_config_dword. Where is this exactly defined? Am 29.08.2016 um 21:07 schrieb Bjorn Helgaas: > On Mon, Aug 29, 2016 at 08:46:17PM +0200, Roland Singer wrote: >> Hi Bjorn, >> >> I am using the bbswitch kernel module to switch off/on the GPU and >> to obtain the GPU power state. >> Obtaining the GPU state immediately after starting the graphical user >> session freezes the system. >> >> This code triggers something, which is responsible for the freeze. >> >> --- >> // Returns 1 if the card is disabled, 0 if enabled >> static int is_card_disabled(void) { >> u32 cfg_word; >> // read first config word which contains Vendor and Device ID. If all bits >> // are enabled, the device is assumed to be off >> pci_read_config_dword(dis_dev, 0, &cfg_word); >> // if one of the bits is not enabled (the card is enabled), the inverted >> // result will be non-zero and hence logical not will make it 0 ("false") >> return !~cfg_word; >> } >> >> static int bbswitch_proc_show(struct seq_file *seqfp, void *p) { >> // show the card state. Example output: 0000:01:00:00 ON >> dis_dev_get(); >> seq_printf(seqfp, "%s %s\n", dev_name(&dis_dev->dev), >> is_card_disabled() ? "OFF" : "ON"); >> dis_dev_put(); >> return 0; >> } >> --- >> >> Either dis_dev_get or pci_read_config_dword is the trigger. > > What happens if you remove the call to is_card_disabled()? Does the > system still freeze if you only do the dis_dev_get()/dis_dev_put()? > >> Link to the bbswitch module source code: >> https://github.com/Bumblebee-Project/bbswitch/blob/master/bbswitch.c#L333 >> >> >> Am 29.08.2016 um 18:02 schrieb Bjorn Helgaas: >>> [+cc linux-acpi, linux-kernel, dri-devel] >>> >>> Hi Roland, >>> >>> I have no idea how to debug this problem. Are you seeing something >>> that suggests it may be a PCI problem? >>> >>> On Tue, Aug 23, 2016 at 11:23:45AM +0200, Roland Singer wrote: >>>> Hi, >>>> >>>> hope somebody can help me fix this kernel problem which affects the following machines: >>>> >>>> - Clevo P651RA (i7-6700HQ/GTX 965M, part of the P6xxRx family which are also affected) >>>> - MSI GE62 Apache Pro (i7-6700HQ/GTX 960M) >>>> - Gigabyte P35V5 (i7-6700HQ/GTX 970M) >>>> - Razer Blade 14" (2016) (i7-6700HQ/GTX 970M) (BIOS 5.11, 04/07/2016) >>>> >>>> >>>> The kernel freezes if the graphical user session (Xorg & Wayland) is >>>> started with a switched off discrete GPU card (NVIDIA). >>>> If the discrete GPU is switched off after the graphical session start, >>>> then everything works as expected, until the graphical session is restarted. >>>> >>>> This problem seams to be linked to specific BIOS settings. If the computer >>>> is started with the following command line: >>>> >>>> acpi_osi=! acpi_osi="Windows 2009" >>>> >>>> then the kernel freeze does not occur anymore. However this required a special >>>> ACPI DSDT firmware patch for the Razer Blade 2016 laptop: >>>> >>>> https://github.com/m4ng0squ4sh/razer_blade_14_2016_acpi_dsdt >>>> >>>> I strongly recommend to fix this in the kernel and I am ready to help and solve >>>> this problem with some help. >>>> >>>> Here is a link to the GitHub issue with further information: >>>> >>>> https://github.com/Bumblebee-Project/Bumblebee/issues/764#issuecomment-241212595 >>>> >>>> Here are some more detailed information: >>>> >>>> https://github.com/Lekensteyn/acpi-stuff/blob/master/Clevo-P651RA/notes.txt >>>> >>>> Hope somebody can help. >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel