Messages in this thread | | | Subject | Re: [PATCH v2] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge | From | AngeloGioacchino Del Regno <> | Date | Tue, 11 Jan 2022 12:05:56 +0100 |
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Il 06/01/22 06:22, CK Hu ha scritto: > Hi, Angelo: > > On Tue, 2022-01-04 at 10:59 +0100, AngeloGioacchino Del Regno wrote: >> DRM bridge drivers are now attaching their DSI device at probe time, >> which requires us to register our DSI host in order to let the bridge >> to probe: this recently started producing an endless -EPROBE_DEFER >> loop on some machines that are using external bridges, like the >> parade-ps8640, found on the ACER Chromebook R13. >> >> Now that the DSI hosts/devices probe sequence is documented, we can >> do adjustments to the mtk_dsi driver as to both fix now and make sure >> to avoid this situation in the future: for this, following what is >> documented in drm_bridge.c, move the mtk_dsi component_add() to the >> mtk_dsi_ops.attach callback and delete it in the detach callback; >> keeping in mind that we are registering a drm_bridge for our DSI, >> which is only used/attached if the DSI Host is bound, it wouldn't >> make sense to keep adding our bridge at probe time (as it would >> be useless to have it if mtk_dsi_ops.attach() fails!), so also move >> that one to the dsi host attach function (and remove it in detach). > > This patch looks good to me, but please add 'Fixes' tag to note to > which patch this patch want to fix. > > Regards, > CK >
Hello, unfortunately I couldn't find a valid commit for a Fixes tag. This started being an issue at some point, when the DRM API was changed to adhere to the documented probe sequence: the MediaTek DSI driver was not the only one that got broken/affected by these changes.
If you have any advice on which commit should be tagged, I'm open for any kind of suggestion.
Thanks, - Angelo
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