<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [NVC1] HDMI audio device only visible after rescan" href="https://bugs.freedesktop.org/show_bug.cgi?id=75985#c29">Comment # 29</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [NVC1] HDMI audio device only visible after rescan" href="https://bugs.freedesktop.org/show_bug.cgi?id=75985">bug 75985</a> from <a class="email" href="mailto:karolherbst@gmail.com" title="Karol Herbst <karolherbst@gmail.com>"> Karol Herbst</a> <pre>(In reply to Daniel Drake from <a href="show_bug.cgi?id=75985#c22">comment #22</a>) > Created <a href="attachment.cgi?id=136369" name="attach_136369" title="GP104: enable HDMI audio device function">attachment 136369</a> <a href="attachment.cgi?id=136369&action=edit" title="GP104: enable HDMI audio device function">[details]</a> <a href='page.cgi?id=splinter.html&bug=75985&attachment=136369'>[review]</a> [review] > GP104: enable HDMI audio device function > > On Asus GL502VS I investigated why the gfx device must be removed before > rescan in the above workarounds. > > The reason is that when Linux first probes the device (before you attempt > the workaround), pci_setup_device() notes that the device is not > multifunction capable. This causes pci_scan_slot() to not bother scanning > the non-zero functions (per the behaviour inside next_fn()). > > I checked and I found that when the 0x488 magic bit is not set, the gfx > device advertises as non-multifunction. After the bit is set, the device > advertises as multi-function. So, after setting the magic bit, removing the > device will cause Linux to re-probe it during the next rescan, taking note > at that point that it is a multi-function device, and proceeding to scan the > functions, finding the audio device at function 1. > > Based on that I have a first attempt at a fix. It's not working though, > audio output is silent (but I did have it working with the previous > workarounds). I'll look closer next week. I think this check against 0x134 can be something like < 0x82 instead. This thing is there since like G82 GPUs and I am sure the HDMI audio device is controlled like this on all those GPUs.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>