Il 08/02/22 09:32, CK Hu ha scritto:
Hi, Angelo:
On Tue, 2022-02-08 at 16:20 +0800, CK Hu wrote:
Hi, Angelo:
On Mon, 2022-01-31 at 09:55 +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).
Cc: stable@vger.kernel.org # 5.15.x Signed-off-by: AngeloGioacchino Del Regno < angelogioacchino.delregno@collabora.com> Reviewed-by: Andrzej Hajda andrzej.hajda@intel.com Reviewed-by: Jagan Teki jagan@amarulasolutions.com
drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++----------
1 file changed, 84 insertions(+), 83 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 5d90d2eb0019..bced4c7d668e 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) mtk_dsi_poweroff(dsi); }
[snip]
- static int mtk_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { struct mtk_dsi *dsi = host_to_dsi(host);
- struct device *dev = host->dev;
- int ret;
dsi->lanes = device->lanes; dsi->format = device->format; dsi->mode_flags = device->mode_flags;
- dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0,
0);
The original would process panel. Why do you remove the panel part? It's better that someone has a platform of DSI->Panel to test this patch.
Sorry, devm_drm_of_get_bridge() has processed the panel part, so for this patch,
Reviewed-by: CK Hu ck.hu@mediatek.com
No worries! Thanks for the review/approval.
Regards, Angelo
Regards, CK