Message ID | 20210910101218.1632297-1-maxime@cerno.tech |
---|---|
Headers | show |
Series | drm/bridge: Make panel and bridge probe order consistent | expand |
On Wed, Sep 29, 2021 at 2:27 PM John Stultz <john.stultz@linaro.org> wrote: > > On Fri, Sep 10, 2021 at 3:12 AM Maxime Ripard <maxime@cerno.tech> wrote: > > > > We've encountered an issue with the RaspberryPi DSI panel that prevented the > > whole display driver from probing. > > > > The issue is described in detail in the commit 7213246a803f ("drm/vc4: dsi: > > Only register our component once a DSI device is attached"), but the basic idea > > is that since the panel is probed through i2c, there's no synchronization > > between its probe and the registration of the MIPI-DSI host it's attached to. > > > > We initially moved the component framework registration to the MIPI-DSI Host > > attach hook to make sure we register our component only when we have a DSI > > device attached to our MIPI-DSI host, and then use lookup our DSI device in our > > bind hook. > > > > However, all the DSI bridges controlled through i2c are only registering their > > associated DSI device in their bridge attach hook, meaning with our change > > above, we never got that far, and therefore ended up in the same situation than > > the one we were trying to fix for panels. > > > > The best practice to avoid those issues is to register its functions only after > > all its dependencies are live. We also shouldn't wait any longer than we should > > to play nice with the other components that are waiting for us, so in our case > > that would mean moving the DSI device registration to the bridge probe. > > > > I also had a look at all the DSI hosts, and it seems that exynos, kirin and msm > > would be affected by this and wouldn't probe anymore after those changes. > > Exynos and kirin seems to be simple enough for a mechanical change (that still > > requires to be tested), but the changes in msm seemed to be far more important > > and I wasn't confortable doing them. > > > Hey Maxime, > Sorry for taking so long to get to this, but now that plumbers is > over I've had a chance to check it out on kirin > > Rob Clark pointed me to his branch with some fixups here: > https://gitlab.freedesktop.org/robclark/msm/-/commits/for-mripard/bridge-rework > > But trying to boot hikey with that, I see the following loop indefinitely: > [ 4.632132] adv7511 2-0039: supply avdd not found, using dummy regulator > [ 4.638961] adv7511 2-0039: supply dvdd not found, using dummy regulator > [ 4.645741] adv7511 2-0039: supply pvdd not found, using dummy regulator > [ 4.652483] adv7511 2-0039: supply a2vdd not found, using dummy regulator > [ 4.659342] adv7511 2-0039: supply v3p3 not found, using dummy regulator > [ 4.666086] adv7511 2-0039: supply v1p2 not found, using dummy regulator > [ 4.681898] adv7511 2-0039: failed to find dsi host I just realized Rob's tree is missing the kirin patch. My apologies! I'll retest and let you know. thanks -john
On Wed, Sep 29, 2021 at 2:51 PM John Stultz <john.stultz@linaro.org> wrote: > > On Wed, Sep 29, 2021 at 2:32 PM John Stultz <john.stultz@linaro.org> wrote: > > On Wed, Sep 29, 2021 at 2:27 PM John Stultz <john.stultz@linaro.org> wrote: > > > On Fri, Sep 10, 2021 at 3:12 AM Maxime Ripard <maxime@cerno.tech> wrote: > > > > The best practice to avoid those issues is to register its functions only after > > > > all its dependencies are live. We also shouldn't wait any longer than we should > > > > to play nice with the other components that are waiting for us, so in our case > > > > that would mean moving the DSI device registration to the bridge probe. > > > > > > > > I also had a look at all the DSI hosts, and it seems that exynos, kirin and msm > > > > would be affected by this and wouldn't probe anymore after those changes. > > > > Exynos and kirin seems to be simple enough for a mechanical change (that still > > > > requires to be tested), but the changes in msm seemed to be far more important > > > > and I wasn't confortable doing them. > > > > > > > > > Hey Maxime, > > > Sorry for taking so long to get to this, but now that plumbers is > > > over I've had a chance to check it out on kirin > > > > > > Rob Clark pointed me to his branch with some fixups here: > > > https://gitlab.freedesktop.org/robclark/msm/-/commits/for-mripard/bridge-rework > > > > > > But trying to boot hikey with that, I see the following loop indefinitely: > > > [ 4.632132] adv7511 2-0039: supply avdd not found, using dummy regulator > > > [ 4.638961] adv7511 2-0039: supply dvdd not found, using dummy regulator > > > [ 4.645741] adv7511 2-0039: supply pvdd not found, using dummy regulator > > > [ 4.652483] adv7511 2-0039: supply a2vdd not found, using dummy regulator > > > [ 4.659342] adv7511 2-0039: supply v3p3 not found, using dummy regulator > > > [ 4.666086] adv7511 2-0039: supply v1p2 not found, using dummy regulator > > > [ 4.681898] adv7511 2-0039: failed to find dsi host > > > > I just realized Rob's tree is missing the kirin patch. My apologies! > > I'll retest and let you know. > > Ok, just retested including the kirin patch and unfortunately I'm > still seeing the same thing. :( > > Will dig a bit and let you know when I find more. Hey Maxime! I chased down the issue. The dsi probe code was still calling drm_of_find_panel_or_bridge() in order to succeed. I've moved the logic that looks for the bridge into the bridge_init and with that it seems to work. Feel free (assuming it looks ok) to fold this change into your kirin patch: https://git.linaro.org/people/john.stultz/android-dev.git/commit/?id=4a35ccc4d7a53f68d6d93da3b47e232a7c75b91d thanks -john