Bug 78507

bug 74266 is relevant.

Please try this hack patch on top of nightly:

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index a13f1f51f68e..2020619e2b98 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -591,7 +591,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
         * is required to retry at least seven times upon receiving AUX_DEFER
         * before giving up the AUX transaction.
         */
-       for (retry = 0; retry < 7; retry++) {
+       for (retry = 0; retry < 50; retry++) {
                err = aux->transfer(aux, msg);
                if (err < 0) {
                        if (err == -EBUSY)
@@ -649,7 +649,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 
                case DP_AUX_I2C_REPLY_DEFER:
                        DRM_DEBUG_KMS("I2C defer\n");
-                       usleep_range(400, 500);
+                       usleep_range(1400, 1500);
                        continue;
 
                default:

Thanks. Can you point me to the instruction on how to apply this patch? Never done that before.

I found this is useful for building upstream kernel from the source:

https://wiki.ubuntu.com/KernelTeam/GitKernelBuild

working on it...

Created attachment 98991 [details]
dmesg_debug_patched.txt

Patch applied on drm-intel-nightly (18a7661946082f5a3b353e50d1ced5d89f864024). But still the same problem. dmesg_debug_patched.txt attached.

Worth mentioning that when default 14.04 kernel (3.13.0-24) is used, I was able to get 1920x1440 resolution (still not native 2560x1600 though).

I'm now using linux kernel 3.13.0-33-generic (latest from Ubuntu trusty updates). The issue is still there: no native resolution on the dock DP output (DP2). It falls back to 1024x768. While the min-DP port on the laptop is always working (DP1).

I will attach updated dmesg_debug output and xrandr output shortly. Can someone help debug this issue? I can provide any further debug info and test the patches.

Created attachment 104525 [details]
20140812_dmesg_debug_DP2.txt

Created attachment 104526 [details]
20140812_xrandr.txt

Please try v3.16 or later.

Created attachment 105898 [details]
20140907_dkms_i915_make.log

Hello,

I have tried the latest v3.17rc4 upstream kernels from http://kernel.ubuntu.com/~kernel-ppa/mainline/ (under v3.17-rc4-utopic folder, "3.17.0-031700rc4_3.17.0-031700rc4.201409071935")

during the installation, I got multiple errors like this:

>Error! Bad return status for module build on kernel: 3.17.0-031700rc4-generic (x86_64)
>Consult /var/lib/dkms/i915-3.15-3.13/0.01/build/make.log for more information.
>Error! Bad return status for module build on kernel: 3.17.0-031700rc4-generic (x86_64)
>Consult /var/lib/dkms/virtualbox/4.3.10/build/make.log for more information.

See attached 20140907_dkms_i915_make.log file. 

Despite the erros, installation went through, and I can reboot OK without OneLink Pro connected. However, if I boot with OneLink Pro connected, I cannot boot into my normal gdm login screen, it goes to terminal directly. See attached 20140908_dmesg_debug_DP2_3.17rc4.log .

I also tried the latest kernels from drm-intel-daily and drm-intel-next, I got the same results.

drm-intel-daily/3.17.0-994_3.17.0-994.201409042205d 
drm-intel-next/3.16.0-997_3.16.0-997.201408270257


Anything else I can help to debug this issue? Thanks.

Created attachment 105899 [details]
20140908_dmesg_debug_DP2_3.17rc4.log

The native resolution is being detected, and presumably the console is coming up in the full mode, so the X failure may be related to the installation problems you saw.

Have you since installed a newer kernel?  If so, do things work now?

I have just tried the latest drm-intel-nightly kernel:

linux-headers-3.18.0-994_3.18.0-994.201412180253_all.deb
linux-headers-3.18.0-994-generic_3.18.0-994.201412180253_amd64.deb
linux-image-3.18.0-994-generic_3.18.0-994.201412180253_amd64.deb


And confirmed that I can get 2560x1600 native resolution now. That's awesome!

Created attachment 110998 [details]
20141218_dmesg_debug_3.18_drm-intel-nightly.txt

Created attachment 111002 [details]
20141218_xrandr.txt

2560x1600 native resolution was recognized correctly now.

I also noticed that now the display port on Lenovo Onelink Pro is designated as DP4 (previously as DP2).

Thanks for the report and testing. Please reopen if the problem persists.