Re: glymur eDP PHY (v8): link trains only at HBR3, all lower rates fail

[Jesse Casco]

Confirmed working. Applied patch on top of next-20260819, panel
trained natively:

DPCD 0x2201 ext MAX_LINK_RATE = 0x14 (HBR2, the panel's actual advertised max)
live link: rate=540000, num_lanes=4, bw_code=0x14
2880x1800 @ 120Hz, 24bpp, pixel clock 709.633 MHz

Thank you for this! Happy to test anything else if it helps.

Jesse

On Tue, Aug 18, 2026 at 6:39 AM Konrad Dybcio
<konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>
> On 8/8/26 7:13 PM, Jesse Casco wrote:
> > Hi Abel,
> >
> > On an ASUS Zenbook A16 (UX3607OA, Snapdragon X2 Elite Extreme) the internal
> > eDP panel never comes up on mainline. It is the link rate: the v8 eDP PHY
> > appears to bring up a usable link only at HBR3.
> >
> > Tested on linux-next next-20260713, next-20260803 and next-20260807, where
> > phy-qcom-edp.c is byte-identical -- so not a recent regression, and the May
> > 2026 series (eDP low-vdiff LDO config, unified swing/pre-emphasis tables,
> > eDP/DP mode switch) is present in the tree tested here. The sweep below is
> > from next-20260803; the machine has since run next-20260807 as its daily
> > driver, where HBR3 still trains every boot.
>
> I mentioned in my submission that this series is required on top:
>
> https://lore.kernel.org/linux-arm-msm/20260622-glymur-edp-phy-v1-0-814b45089ac9@xxxxxxxxxxxxxxxx/
>
> Konrad



-- 
Jesse Casco