Re: [PATCH v3 7/7] drm/vc4: kms: Don't disable the muxing of an active CRTC

[Thomas Zimmermann]

Hi

Am 19.11.20 um 15:32 schrieb Maxime Ripard:

On Thu, Nov 19, 2020 at 10:12:43AM +0100, Thomas Zimmermann wrote:

Hi

Am 05.11.20 um 14:56 schrieb Maxime Ripard:

The current HVS muxing code will consider the CRTCs in a given state to
setup their muxing in the HVS, and disable the other CRTCs muxes.

However, it's valid to only update a single CRTC with a state, and in this
situation we would mux out a CRTC that was enabled but left untouched by
the new state.

Fix this by setting a flag on the CRTC state when the muxing has been
changed, and only change the muxing configuration when that flag is there.

Fixes: 87ebcd42fb7b ("drm/vc4: crtc: Assign output to channel automatically")
Reviewed-by: Hoegeun Kwon <hoegeun.k...@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.k...@samsung.com>
Signed-off-by: Maxime Ripard <max...@cerno.tech>
---
   drivers/gpu/drm/vc4/vc4_drv.h |  1 +
   drivers/gpu/drm/vc4/vc4_kms.c | 82 ++++++++++++++++++++---------------
   2 files changed, 48 insertions(+), 35 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 014113823647..325b53ff11b3 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -524,6 +524,7 @@ struct vc4_crtc_state {
        struct drm_mm_node mm;
        bool feed_txp;
        bool txp_armed;
+       bool needs_muxing;

Maybe rather 'update_muxing'.

More generally, I'd separate fields that contain actual CRTC state, such
assigned_channel, from those that only contain transitional state during
update-commit, such as needs_muxing.

How would you separate them?

I'll use your other suggestions, thanks!

Best regards
Thomas

I'd put the transitional state at the end of the struct and put a comment above. Something like 'Transitional state below; only valid during atomic commits'.

Maxime

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

OpenPGP_0x680DC11D530B7A23.asc
Description: application/pgp-keys

OpenPGP_signature
Description: OpenPGP digital signature

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel