Hi Peter,
On Fri, May 27, 2016 at 11:31:23PM +0200, Peter Wu wrote:
On Fri, May 27, 2016 at 02:01:39PM +0100, Emil Velikov wrote:
On 24 May 2016 at 23:53, Peter Wu peter@lekensteyn.nl wrote:
[snip]
@@ -273,14 +296,14 @@ static bool nouveau_dsm_detect(void) vga_count++;
nouveau_dsm_pci_probe(pdev, &has_mux, &has_optimus,
&has_optimus_flags);
&has_optimus_flags, &has_power_resources); } while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_3D << 8, pdev)) != NULL) { vga_count++; nouveau_dsm_pci_probe(pdev, &has_mux, &has_optimus,
&has_optimus_flags);
&has_optimus_flags, &has_power_resources); }This and earlier patch break things in a subtle way.
Namely: upon the second (and any later) call into the nouveau_dsm_pci_probe() function, the had_foo flags are reset. Thus only the specifics of the _final_ device are being used (at a later stage). IMHO one should change that to "_any_ device", which will match the original code and the actual intent further down in the file.
The flags are only reset if any of the MUX or Optimus handles are found. If both are missing, the flags are not overridden. This is from patch 1:
/* Does not look like a Nvidia device. */if (!supports_mux && !supports_opt)return;The reason why later calls override early ones is because some Optimus laptops have the _DSM method on both the Intel GPU (00:02.0) and the Nvidia one (01:00.0).
Sounds like you may want to check for pdev->vendor == PCI_VENDOR_ID_NVIDIA or export pci_get_dev_by_id() and use that to match for class and vendor.
Best regards,
Lukas