This is a note to let you know that I've just added the patch titled
drm/sun4i: Fix TCON clock and regmap initialization sequence
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: drm-sun4i-fix-tcon-clock-and-regmap-initialization-sequence.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Sun Mar 18 16:55:33 CET 2018
From: Chen-Yu Tsai wens@csie.org Date: Thu, 9 Mar 2017 18:05:24 +0800 Subject: drm/sun4i: Fix TCON clock and regmap initialization sequence
From: Chen-Yu Tsai wens@csie.org
[ Upstream commit 4c7f16d14a33a9cfb4af9cb780d8a73bcca64a92 ]
The TCON driver calls sun4i_tcon_init_regmap and sun4i_tcon_init_clocks in its bind function. The former creates a regmap and writes to several register to clear its configuration to a known default. The latter initializes various clocks. This includes enabling the bus clock for register access and creating the dotclock.
In order for the first step's writes to work, the bus clock must be enabled which is done in the second step. but the dotclock's ops use the regmap created in the first step.
Rearrange the function calls such that the clocks are initialized before the regmap, and split out the dot clock creation to after the regmap is initialized.
Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Chen-Yu Tsai wens@csie.org Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -336,12 +336,11 @@ static int sun4i_tcon_init_clocks(struct } }
- return sun4i_dclk_create(dev, tcon); + return 0; }
static void sun4i_tcon_free_clocks(struct sun4i_tcon *tcon) { - sun4i_dclk_free(tcon); clk_disable_unprepare(tcon->clk); }
@@ -506,22 +505,28 @@ static int sun4i_tcon_bind(struct device return ret; }
+ ret = sun4i_tcon_init_clocks(dev, tcon); + if (ret) { + dev_err(dev, "Couldn't init our TCON clocks\n"); + goto err_assert_reset; + } + ret = sun4i_tcon_init_regmap(dev, tcon); if (ret) { dev_err(dev, "Couldn't init our TCON regmap\n"); - goto err_assert_reset; + goto err_free_clocks; }
- ret = sun4i_tcon_init_clocks(dev, tcon); + ret = sun4i_dclk_create(dev, tcon); if (ret) { - dev_err(dev, "Couldn't init our TCON clocks\n"); - goto err_assert_reset; + dev_err(dev, "Couldn't create our TCON dot clock\n"); + goto err_free_clocks; }
ret = sun4i_tcon_init_irq(dev, tcon); if (ret) { dev_err(dev, "Couldn't init our TCON interrupts\n"); - goto err_free_clocks; + goto err_free_dotclock; }
ret = sun4i_rgb_init(drm); @@ -530,6 +535,8 @@ static int sun4i_tcon_bind(struct device
return 0;
+err_free_dotclock: + sun4i_dclk_free(tcon); err_free_clocks: sun4i_tcon_free_clocks(tcon); err_assert_reset: @@ -542,6 +549,7 @@ static void sun4i_tcon_unbind(struct dev { struct sun4i_tcon *tcon = dev_get_drvdata(dev);
+ sun4i_dclk_free(tcon); sun4i_tcon_free_clocks(tcon); }
Patches currently in stable-queue which might be from wens@csie.org are
queue-4.9/drm-sun4i-fix-up-error-path-cleanup-for-master-bind-function.patch queue-4.9/drm-sun4i-set-drm_crtc.port-to-the-underlying-tcon-s-output-port-node.patch queue-4.9/drm-sun4i-fix-tcon-clock-and-regmap-initialization-sequence.patch queue-4.9/clk-sunxi-ng-a33-add-offset-and-minimum-value-for-ddr1-pll-n-factor.patch