On Sun, Apr 15, 2018 at 07:17:46PM +0200, Pali Rohár wrote:
On Saturday 14 April 2018 13:17:11 Lukas Wunner wrote:
On Sat, Apr 14, 2018 at 12:49:50PM +0200, Pali Rohár wrote:
On Saturday 14 April 2018 12:45:12 Lukas Wunner wrote:
On Thu, Apr 12, 2018 at 10:15:41PM +0800, Kai-Heng Feng wrote:
Do you have any suggestion to check if it connects to the system via Thunderbolt?
Just use pci_is_thunderbolt_attached(), introduced by 8531e283bee6, like this:
if (check_dell_switchable_gfx(pci) && !pci_is_thunderbolt_attached(pci))
And what about PCI-e device attached to ExpressCard slot?
I don't know of a bullet-proof way to recognize those. In theory one could check if the PCIe port above the GPU is a non-hotplug root port, but I think there are machines with hotplug capable root ports with GPUs below them that aren't actually removable.
However I think ExpressCard-attached GPUs were rare, much less ones with integrated HDA controller, so in reality that's probably a non-issue.
Hm... maybe another idea: Is it possible to detect which audio pci device belongs to graphics card via vga_switcheroo? Currently, looking at output it is same PCI device as graphic card, just different PCI function.
No, the DRM drivers don't filter ExpressCard-attached GPUs when registering with vga_switcheroo. They do filter Thunderbolt- attached GPUs.
The ExpressCard 2.0 spec defines some ACPI stuff that *might* be used to recognize root ports that are ExpressCard slots, but I'm not sure how reliable that is. I don't have such a machine and have no experience with it.
This is from the MacBookPro8,3 DSDT:
Device (RP04) { Name (_ADR, 0x001C0003) OperationRegion (A1E0, PCI_Config, 0x19, 0x01) Field (A1E0, ByteAcc, NoLock, Preserve) { SECB, 8 }
Device (EXCD) { Name (_ADR, 0x00) Name (_SUN, 0x01) Method (_RMV, 0, NotSerialized) { Return (0x01) }
Name (_EJD, "\_SB.PCI0.EHC2.HUBN.PRTN.PRT4") } ... }
Thanks,
Lukas