* [PATCH] pwm: mtk_disp: Fix the disable flow of disp_pwm
@ 2023-05-15 6:18 Shuijing Li
2023-05-15 14:03 ` Uwe Kleine-König
0 siblings, 1 reply; 2+ messages in thread
From: Shuijing Li @ 2023-05-15 6:18 UTC (permalink / raw)
To: thierry.reding, matthias.bgg, angelogioacchino.delregno
Cc: devicetree, linux-pwm, linux-kernel, linux-arm-kernel,
linux-mediatek, Project_Global_Chrome_Upstream_Group, jitao.shi,
Shuijing Li
There is a flow error in the original mtk_disp_pwm_apply() function.
If this function is called when the clock is disabled, there will be a
chance to operate the disp_pwm register, resulting in disp_pwm exception.
Fix this accordingly.
Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
---
drivers/pwm/pwm-mtk-disp.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 79e321e96f56..cb699fa9a5ae 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -80,10 +80,9 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
return -EINVAL;
if (!state->enabled) {
- mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
- 0x0);
-
if (mdp->enabled) {
+ mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
+ mdp->data->enable_mask, 0x0);
clk_disable_unprepare(mdp->clk_mm);
clk_disable_unprepare(mdp->clk_main);
}
--
2.40.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] pwm: mtk_disp: Fix the disable flow of disp_pwm
2023-05-15 6:18 [PATCH] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
@ 2023-05-15 14:03 ` Uwe Kleine-König
0 siblings, 0 replies; 2+ messages in thread
From: Uwe Kleine-König @ 2023-05-15 14:03 UTC (permalink / raw)
To: Shuijing Li
Cc: thierry.reding, matthias.bgg, angelogioacchino.delregno,
devicetree, linux-pwm, linux-kernel, linux-arm-kernel,
linux-mediatek, Project_Global_Chrome_Upstream_Group, jitao.shi
[-- Attachment #1: Type: text/plain, Size: 1442 bytes --]
On Mon, May 15, 2023 at 02:18:45PM +0800, Shuijing Li wrote:
> There is a flow error in the original mtk_disp_pwm_apply() function.
> If this function is called when the clock is disabled, there will be a
> chance to operate the disp_pwm register, resulting in disp_pwm exception.
> Fix this accordingly.
>
> Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
> ---
> drivers/pwm/pwm-mtk-disp.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> index 79e321e96f56..cb699fa9a5ae 100644
> --- a/drivers/pwm/pwm-mtk-disp.c
> +++ b/drivers/pwm/pwm-mtk-disp.c
> @@ -80,10 +80,9 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> return -EINVAL;
>
> if (!state->enabled) {
> - mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> - 0x0);
> -
> if (mdp->enabled) {
> + mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
> + mdp->data->enable_mask, 0x0);
> clk_disable_unprepare(mdp->clk_mm);
> clk_disable_unprepare(mdp->clk_main);
Instead of
if (A) {
if (B) {
something();
}
}
you can make this
if (A && B) {
something();
}
Otherwise looks ok.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2023-05-15 14:04 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-05-15 6:18 [PATCH] pwm: mtk_disp: Fix the disable flow of disp_pwm Shuijing Li
2023-05-15 14:03 ` Uwe Kleine-König
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).