2024-06-10 10:54:49

by Dan Carpenter

Subject: [PATCH v2] drm/bridge: it6505: remove unnecessary NULL checks

Smatch complains correctly that the NULL checking isn't consistent:

drivers/gpu/drm/bridge/ite-it6505.c:2583 it6505_poweron()
error: we previously assumed 'pdata->pwr18' could be null
(see line 2569)

These the ->pwr18 pointer is allocated during probe using the
devm_regulator_get() function. If CONFIG_REGULATOR is disabled then,
yes, it can return NULL but in that case regulator_enable() and
disable() functions are no-ops so passing a NULL pointer is okay.

Smatch is correct that the NULL checks are inconsistent but the
fix is to delete the unnecessary NULL checking. Do the same for
"pdata->ovdd" as well.

Signed-off-by: Dan Carpenter <[email protected]>
---
v2: In the first patch, I added a NULL check but that wasn't necessary
or correct.

drivers/gpu/drm/bridge/ite-it6505.c | 43 ++++++++++++-----------------
1 file changed, 18 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 3f68c82888c2..d89d1bb9a8ec 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2566,24 +2566,21 @@ static int it6505_poweron(struct it6505 *it6505)
return 0;
}

- if (pdata->pwr18) {
- err = regulator_enable(pdata->pwr18);
- if (err) {
- DRM_DEV_DEBUG_DRIVER(dev, "Failed to enable VDD18: %d",
- err);
- return err;
- }
+ err = regulator_enable(pdata->pwr18);
+ if (err) {
+ DRM_DEV_DEBUG_DRIVER(dev, "Failed to enable VDD18: %d",
+ err);
+ return err;
}

- if (pdata->ovdd) {
- /* time interval between IVDD and OVDD at least be 1ms */
- usleep_range(1000, 2000);
- err = regulator_enable(pdata->ovdd);
- if (err) {
- regulator_disable(pdata->pwr18);
- return err;
- }
+ /* time interval between IVDD and OVDD at least be 1ms */
+ usleep_range(1000, 2000);
+ err = regulator_enable(pdata->ovdd);
+ if (err) {
+ regulator_disable(pdata->pwr18);
+ return err;
}
+
/* time interval between OVDD and SYSRSTN at least be 10ms */
if (pdata->gpiod_reset) {
usleep_range(10000, 20000);
@@ -2618,17 +2615,13 @@ static int it6505_poweroff(struct it6505 *it6505)
if (pdata->gpiod_reset)
gpiod_set_value_cansleep(pdata->gpiod_reset, 0);

- if (pdata->pwr18) {
- err = regulator_disable(pdata->pwr18);
- if (err)
- return err;
- }
+ err = regulator_disable(pdata->pwr18);
+ if (err)
+ return err;

- if (pdata->ovdd) {
- err = regulator_disable(pdata->ovdd);
- if (err)
- return err;
- }
+ err = regulator_disable(pdata->ovdd);
+ if (err)
+ return err;

it6505->powered = false;
it6505->sink_count = 0;
--
2.39.2

2024-06-10 11:55:32

by Robert Foss

Subject: Re: [PATCH v2] drm/bridge: it6505: remove unnecessary NULL checks

On Mon, 10 Jun 2024 13:50:26 +0300, Dan Carpenter wrote:
> Smatch complains correctly that the NULL checking isn't consistent:
>
> drivers/gpu/drm/bridge/ite-it6505.c:2583 it6505_poweron()
> error: we previously assumed 'pdata->pwr18' could be null
> (see line 2569)
>
> These the ->pwr18 pointer is allocated during probe using the
> devm_regulator_get() function. If CONFIG_REGULATOR is disabled then,
> yes, it can return NULL but in that case regulator_enable() and
> disable() functions are no-ops so passing a NULL pointer is okay.
>
> [...]

Applied, thanks!

[1/1] drm/bridge: it6505: remove unnecessary NULL checks
(no commit info)



Rob