<html><body><p> <pre> On Wed, 2025-06-25 at 14:49 -0400, Nícolas F. R. A. Prado wrote: > External email : Please do not click links or open attachments until you have verified the sender or the content. > > > On Wed, 2025-06-25 at 17:54 +0800, Liankun Yang wrote: > > By adjusting the order of link training and relocating it to HPD, > > link training can identify the usability of each lane in the current > > link. > > > > It also supports handling signal instability and weakness due to > > environmental issues, enabling the acquisition of a stable bandwidth > > for the current link. Subsequently, DP work can proceed based on > > the actual maximum bandwidth. > > > > It should training in the hpd event thread. > > Check the mode with lane count and link rate of training. > > > > If we're eDP and capabilities were already parsed we can skip > > reading again because eDP panels aren't hotpluggable hence the > > caps and training information won't ever change in a boot life > > > > Therefore, bridge typec judgment is required for edp training in > > atomic_enable function. > > > > Signed-off-by: Liankun Yang <liankun.yang@mediatek.com> > > --- > > Change in V4: > > - Tested the internal eDP display on MT8195 Tomato and it is fine. > > Per suggestion from the previous thread: > > https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20250318140236.13650-2-liankun.yang@mediatek.com/__;!!CTRNKA9wMg0ARbw!g0Ii2UaT9Wu1FktoGneG4gHV_zwIAwcqEihEA0W4XHKOW2vv7i5MLlekFB9AbbBJvWKvbyaiQFkF-JpPcq0$ > > Hi, > > I tested this patch on MT8195 Tomato, on top of next-20250625. Indeed > the internal eDP display is unaffected by this commit: it still works > fine. > > The external displays though not so much. I tested 3 different > displays, using 2 different USBC-to-HDMI adapters, and in all cases the > behavior was the same: > - Before the patch, the image on the display is completely corrupted > and unusable. The only discernible element on the display is the mouse > cursor, which shows perfectly fine. Occasionally no image will be shown > at all, but most of the times, the behavior is as described. > - After the patch, nothing ever shows at all on the display. It is > always black. > > So while the external display support on Tomato is basically broken as > of the latest next, this patch seems to regress the support even > further. Hi, Nicolas: Have external display worked normally in previous version? If no, I think this patch just let external display change from one bad state to another bad state. If yes, I think we should fix this problem first, and then apply this patch to test. Regards, CK > > -- > Thanks, > > Nícolas </pre> </p></body></html><pre>************* MEDIATEK Confidentiality Notice ******************** The information contained in this e-mail message (including any attachments) may be confidential, proprietary, privileged, or otherwise exempt from disclosure under applicable laws. It is intended to be conveyed only to the designated recipient(s). Any use, dissemination, distribution, printing, retaining or copying of this e-mail (including its attachments) by unintended recipient(s) is strictly prohibited and may be unlawful. If you are not an intended recipient of this e-mail, or believe that you have received this e-mail in error, please notify the sender immediately (by replying to this e-mail), delete any and all copies of this e-mail (including any attachments) from your system, and do not disclose the content of this e-mail to any other person. Thank you! </pre>