Messages in this thread | | | From | Dmitry Baryshkov <> | Date | Tue, 5 Apr 2022 00:13:03 +0300 | Subject | Re: [PATCH v6 6/8] drm/msm/dp: remove unnecessary delay during boot |
| |
On Mon, 4 Apr 2022 at 16:53, Sankeerth Billakanti (QUIC) <quic_sbillaka@quicinc.com> wrote: > > Hi Doug, > > > On Wed, Mar 30, 2022 at 9:04 AM Sankeerth Billakanti > > <quic_sbillaka@quicinc.com> wrote: > > > > > > Remove the unnecessary delay in executing the EV_HPD_INIT_SETUP > > event. > > > > Tell me more and put it in the commit message! Why did it used to be > > necessary and why is it no longer necessary? Inquiring minds want to know. > > > > Okay. I will add proper description. The DP phy is shared with usb and executing the > dp phy_init before the usb phy_init was causing usb devices to not function.
I always wondered, how does this work for the 4-lane DP dongles, where there is no USB mode/lanes?
> Earlier, enabling phy_init was done when the EV_HPD_INIT_SETUP event was executed. > So, we had scheduled it to execute after 10 second to let the usb driver complete the phy_init first. > > Kuogee made the below change to move the DP phy_init to execute after the DP is connected > https://patchwork.kernel.org/project/linux-arm-msm/patch/1642531648-8448-2-git-send-email-quic_khsieh@quicinc.com/ > > So, there is no need for the DP driver to wait 10 seconds for the phy initialization anymore. > > eDP PHY is not shared with usb. So, it can be programmed anytime, hence not needing any delay.
-- With best wishes Dmitry
| |