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@xxxxxxxxxxxxxxx> # 5.15.x
Signed-off-by: AngeloGioacchino Del Regno <
angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Reviewed-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxx>
No worries! Thanks for the review/approval.
Regards,
Angelo
Regards,
CK
