All of lore.kernel.org
 help / color / mirror / Atom feed
From: Maxime Ripard <maxime@cerno.tech>
To: Emma Anholt <emma@anholt.net>, Maxime Ripard <mripard@kernel.org>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	Dave Stevenson <dave.stevenson@raspberrypi.com>,
	Maxime Ripard <maxime@cerno.tech>
Subject: [PATCH 6/6] drm/vc4: dsi: Remove entry to ULPS from vc4_dsi post_disable
Date: Wed, 07 Dec 2022 11:22:49 +0100	[thread overview]
Message-ID: <20221207-rpi-dsi-bridge-v1-6-8f68ee0b0adb@cerno.tech> (raw)
In-Reply-To: <20221207-rpi-dsi-bridge-v1-0-8f68ee0b0adb@cerno.tech>

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

Post_disable was sending the D-PHY sequence to put any device
into ULPS suspend mode, and then cutting power to the DSI block.
The power-on reset state of the DSI block is for DSI to be in
an operational state, not ULPS, so it then never sent the sequence
for exiting ULPS. Any attached device that didn't have an external
reset therefore remained in ULPS / standby, and didn't function.

Use of ULPS isn't well specified in DRM, therefore remove entering
it to avoid the above situation.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index a7b8ffd995b0..4f3805528aa1 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -813,8 +813,6 @@ static void vc4_dsi_bridge_post_disable(struct drm_bridge *bridge,
 	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
 	struct device *dev = &dsi->pdev->dev;
 
-	vc4_dsi_ulps(dsi, true);
-
 	clk_disable_unprepare(dsi->pll_phy_clock);
 	clk_disable_unprepare(dsi->escape_clock);
 	clk_disable_unprepare(dsi->pixel_clock);

-- 
2.38.1

WARNING: multiple messages have this Message-ID (diff)
From: Maxime Ripard <maxime@cerno.tech>
To: Emma Anholt <emma@anholt.net>, Maxime Ripard <mripard@kernel.org>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>
Cc: Maxime Ripard <maxime@cerno.tech>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Dave Stevenson <dave.stevenson@raspberrypi.com>
Subject: [PATCH 6/6] drm/vc4: dsi: Remove entry to ULPS from vc4_dsi post_disable
Date: Wed, 07 Dec 2022 11:22:49 +0100	[thread overview]
Message-ID: <20221207-rpi-dsi-bridge-v1-6-8f68ee0b0adb@cerno.tech> (raw)
In-Reply-To: <20221207-rpi-dsi-bridge-v1-0-8f68ee0b0adb@cerno.tech>

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

Post_disable was sending the D-PHY sequence to put any device
into ULPS suspend mode, and then cutting power to the DSI block.
The power-on reset state of the DSI block is for DSI to be in
an operational state, not ULPS, so it then never sent the sequence
for exiting ULPS. Any attached device that didn't have an external
reset therefore remained in ULPS / standby, and didn't function.

Use of ULPS isn't well specified in DRM, therefore remove entering
it to avoid the above situation.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index a7b8ffd995b0..4f3805528aa1 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -813,8 +813,6 @@ static void vc4_dsi_bridge_post_disable(struct drm_bridge *bridge,
 	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
 	struct device *dev = &dsi->pdev->dev;
 
-	vc4_dsi_ulps(dsi, true);
-
 	clk_disable_unprepare(dsi->pll_phy_clock);
 	clk_disable_unprepare(dsi->escape_clock);
 	clk_disable_unprepare(dsi->pixel_clock);

-- 
2.38.1

  parent reply	other threads:[~2022-12-07 10:28 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-07 10:22 [PATCH 0/6] drm/vc4: dsi: Conversion to bridge Maxime Ripard
2022-12-07 10:22 ` Maxime Ripard
2022-12-07 10:22 ` [PATCH 1/6] drm/vc4: dsi: Rename bridge to out_bridge Maxime Ripard
2022-12-07 10:22   ` Maxime Ripard
2022-12-07 10:22 ` [PATCH 2/6] drm/vc4: dsi: Move initialisation to encoder_mode_set Maxime Ripard
2022-12-07 10:22   ` Maxime Ripard
2022-12-07 10:22 ` [PATCH 3/6] drm/vc4: dsi: Remove splitting the bridge chain from the driver Maxime Ripard
2022-12-07 10:22   ` Maxime Ripard
2022-12-07 10:22 ` [PATCH 4/6] drm/vc4: dsi: Convert to use atomic operations Maxime Ripard
2022-12-07 10:22   ` Maxime Ripard
2022-12-07 10:22 ` [PATCH 5/6] drm/vc4: dsi: Convert to using a bridge instead of encoder Maxime Ripard
2022-12-07 10:22   ` Maxime Ripard
2022-12-07 10:22 ` Maxime Ripard [this message]
2022-12-07 10:22   ` [PATCH 6/6] drm/vc4: dsi: Remove entry to ULPS from vc4_dsi post_disable Maxime Ripard
2022-12-15  7:59 ` [PATCH 0/6] drm/vc4: dsi: Conversion to bridge Maxime Ripard
2022-12-15  7:59   ` Maxime Ripard

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20221207-rpi-dsi-bridge-v1-6-8f68ee0b0adb@cerno.tech \
    --to=maxime@cerno.tech \
    --cc=airlied@gmail.com \
    --cc=daniel@ffwll.ch \
    --cc=dave.stevenson@raspberrypi.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=emma@anholt.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mripard@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.