lkml.org 
[lkml]   [2023]   [May]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] drm: sun4i_tcon: use devm_clk_get_enabled in `sun4i_tcon_init_clocks`
From
On 2023/4/30 19:23, XuDong Liu wrote:
> 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>
> ---
> The issue is discovered by static analysis, and the patch is not tested
> yet.
> ---
> 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 523a6d787921..936796851ffd 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 = {
Ping?

\
 
 \ /
  Last update: 2023-05-11 08:22    [W:0.040 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site