[PATCH 6.4 252/800] drm: sun4i_tcon: use devm_clk_get_enabled in `sun4i_tcon_init_clocks`

Greg Kroah-Hartman
2023-07-16T20:04:34Z

From: XuDong Liu <m202071377@hust.edu.cn>

[ Upstream commit 123ee07ba5b7123e0ce0e0f9d64938026c16a2ce ]

Smatch reports:
drivers/gpu/drm/sun4i/sun4i_tcon.c:805 sun4i_tcon_init_clocks() warn:
'tcon->clk' from clk_prepare_enable() not released on lines: 792,801.

In the function sun4i_tcon_init_clocks(), tcon->clk and tcon->sclk0 are
not disabled in the error handling, which affects the release of
these variable. Although sun4i_tcon_bind(), which calls
sun4i_tcon_init_clocks(), use sun4i_tcon_free_clocks to disable the
variables mentioned, but the error handling branch of
sun4i_tcon_init_clocks() ignores the required disable process.

To fix this issue, use the devm_clk_get_enabled to automatically
balance enable and disabled calls. As original implementation use
sun4i_tcon_free_clocks() to disable clk explicitly, we delete the
related calls and error handling that are no longer needed.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Fixes: b14e945bda8a ("drm/sun4i: tcon: Prepare and enable TCON channel 0 clock at init")
Fixes: 8e9240472522 ("drm/sun4i: support TCONs without channel 1")
Fixes: 34d698f6e349 ("drm/sun4i: Add has_channel_0 TCON quirk")
Signed-off-by: XuDong Liu <m202071377@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20230430112347.4689-1-m202071377@hust.edu.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/sun4i/sun4i_tcon.c | 19 ++++---------------
1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 523a6d7879210..936796851ffd3 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -778,21 +778,19 @@ static irqreturn_t sun4i_tcon_handler(int irq, void *private)
static int sun4i_tcon_init_clocks(struct device *dev,
struct sun4i_tcon *tcon)
{
- tcon->clk = devm_clk_get(dev, "ahb");
+ tcon->clk = devm_clk_get_enabled(dev, "ahb");
if (IS_ERR(tcon->clk)) {
dev_err(dev, "Couldn't get the TCON bus clock\n");
return PTR_ERR(tcon->clk);
}
- clk_prepare_enable(tcon->clk);

if (tcon->quirks->has_channel_0) {
- tcon->sclk0 = devm_clk_get(dev, "tcon-ch0");
+ tcon->sclk0 = devm_clk_get_enabled(dev, "tcon-ch0");
if (IS_ERR(tcon->sclk0)) {
dev_err(dev, "Couldn't get the TCON channel 0 clock\n");
return PTR_ERR(tcon->sclk0);
}
}
- clk_prepare_enable(tcon->sclk0);

if (tcon->quirks->has_channel_1) {
tcon->sclk1 = devm_clk_get(dev, "tcon-ch1");
@@ -805,12 +803,6 @@ static int sun4i_tcon_init_clocks(struct device *dev,
return 0;
}

-static void sun4i_tcon_free_clocks(struct sun4i_tcon *tcon)
-{
- clk_disable_unprepare(tcon->sclk0);
- clk_disable_unprepare(tcon->clk);
-}
-
static int sun4i_tcon_init_irq(struct device *dev,
struct sun4i_tcon *tcon)
{
@@ -1223,14 +1215,14 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
ret = sun4i_tcon_init_regmap(dev, tcon);
if (ret) {
dev_err(dev, "Couldn't init our TCON regmap\n");
- goto err_free_clocks;
+ goto err_assert_reset;
}

if (tcon->quirks->has_channel_0) {
ret = sun4i_dclk_create(dev, tcon);
if (ret) {
dev_err(dev, "Couldn't create our TCON dot clock\n");
- goto err_free_clocks;
+ goto err_assert_reset;
}
}

@@ -1293,8 +1285,6 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
err_free_dotclock:
if (tcon->quirks->has_channel_0)
sun4i_dclk_free(tcon);
-err_free_clocks:
- sun4i_tcon_free_clocks(tcon);
err_assert_reset:
reset_control_assert(tcon->lcd_rst);
return ret;
@@ -1308,7 +1298,6 @@ static void sun4i_tcon_unbind(struct device *dev, struct device *master,
list_del(&tcon->list);
if (tcon->quirks->has_channel_0)
sun4i_dclk_free(tcon);
- sun4i_tcon_free_clocks(tcon);
}

static const struct component_ops sun4i_tcon_ops = {
--
2.39.2