Revision bc9db5ad3253c8e17969bd802c47b73e63f125ab authored by Ville Syrjälä on 11 November 2016, 17:14:24 UTC, committed by Jani Nikula on 16 November 2016, 08:06:14 UTC
My heuristic for detecting type 1 DVI DP++ adaptors based on the VBT port information apparently didn't survive the reality of buggy VBTs. In this particular case we have a machine with a natice HDMI port, but the VBT tells us it's a DP++ port based on its capabilities. The dvo_port information in VBT does claim that we're dealing with a HDMI port though, but we have other machines which do the same even when they actually have DP++ ports. So that piece of information alone isn't sufficient to tell the two apart. After staring at a bunch of VBTs from various machines, I have to conclude that the only other semi-reliable clue we can use is the presence of the AUX channel in the VBT. On this particular machine AUX channel is specified as zero, whereas on some of the other machines which listed the DP++ port as HDMI have a non-zero AUX channel. I've also seen VBTs which have dvo_port a DP but have a zero AUX channel. I believe those we need to treat as DP ports, so we'll limit the AUX channel check to just the cases where dvo_port is HDMI. If we encounter any more serious failures with this heuristic I think we'll have to have to throw it out entirely. But that could mean that there is a risk of type 1 DVI dongle users getting greeted by a black screen, so I'd rather not go there unless absolutely necessary. v2: Remove the duplicate PORT_A check (Daniel) Fix some typos in the commit message Cc: Daniel Otero <daniel.otero@outlook.com> Cc: stable@vger.kernel.org Tested-by: Daniel Otero <daniel.otero@outlook.com> Fixes: d61992565bd3 ("drm/i915: Determine DP++ type 1 DVI adaptor presence based on VBT") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97994 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1478884464-14251-1-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (cherry picked from commit 7a17995a3dc8613f778a9e2fd20e870f17789544) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
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accessibility | ||
acpi | ||
amba | ||
android | ||
ata | ||
atm | ||
auxdisplay | ||
base | ||
bcma | ||
block | ||
bluetooth | ||
bus | ||
cdrom | ||
char | ||
clk | ||
clocksource | ||
connector | ||
cpufreq | ||
cpuidle | ||
crypto | ||
dax | ||
dca | ||
devfreq | ||
dio | ||
dma | ||
dma-buf | ||
edac | ||
eisa | ||
extcon | ||
firewire | ||
firmware | ||
fmc | ||
fpga | ||
gpio | ||
gpu | ||
hid | ||
hsi | ||
hv | ||
hwmon | ||
hwspinlock | ||
hwtracing | ||
i2c | ||
ide | ||
idle | ||
iio | ||
infiniband | ||
input | ||
iommu | ||
ipack | ||
irqchip | ||
isdn | ||
leds | ||
lguest | ||
lightnvm | ||
macintosh | ||
mailbox | ||
mcb | ||
md | ||
media | ||
memory | ||
memstick | ||
message | ||
mfd | ||
misc | ||
mmc | ||
mtd | ||
net | ||
nfc | ||
ntb | ||
nubus | ||
nvdimm | ||
nvme | ||
nvmem | ||
of | ||
oprofile | ||
parisc | ||
parport | ||
pci | ||
pcmcia | ||
perf | ||
phy | ||
pinctrl | ||
platform | ||
pnp | ||
power | ||
powercap | ||
pps | ||
ps3 | ||
ptp | ||
pwm | ||
rapidio | ||
ras | ||
regulator | ||
remoteproc | ||
reset | ||
rpmsg | ||
rtc | ||
s390 | ||
sbus | ||
scsi | ||
sfi | ||
sh | ||
sn | ||
soc | ||
spi | ||
spmi | ||
ssb | ||
staging | ||
target | ||
tc | ||
thermal | ||
thunderbolt | ||
tty | ||
uio | ||
usb | ||
uwb | ||
vfio | ||
vhost | ||
video | ||
virt | ||
virtio | ||
vlynq | ||
vme | ||
w1 | ||
watchdog | ||
xen | ||
zorro | ||
Kconfig | -rw-r--r-- | 3.3 KB |
Makefile | -rw-r--r-- | 4.9 KB |
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