diff mbox series

drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()

Message ID 20260916182412.2091681-1-vulab@iscas.ac.cn (mailing list archive)
State New
Headers
Series drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux() |

Commit Message

Wentao Liang Sept. 16, 2026, 6:24 p.m. UTC 
of_find_device_by_node() takes a reference to the TCON TOP device
which the error paths release, but the success path returns without
doing so.  Drop the reference before returning success.

Fixes: 0305189afb32 ("drm/sun4i: tcon: Add support for R40 TCON")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

sashiko-bot@kernel.org Sept. 16, 2026, 6:30 p.m. UTC | #1 
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] drm/sun4i: misapplied patch causes build failure
--

commit 576ab0ea69ae3e401d6153bcb00f1e660850ae75
Author: Wentao Liang <vulab@iscas.ac.cn>

drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()

This commit attempts to fix a claimed reference leak in the success path of
sun8i_r40_tcon_tv_set_mux(). However, the patch modifies the wrong function
and introduces a build failure.

Fixes: 0305189afb32 ("drm/sun4i: tcon: Add support for R40 TCON")
Cc: stable@vger.kernel.org

> drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()
> 
> of_find_device_by_node() takes a reference to the TCON TOP device
> which the error paths release, but the success path returns without
> doing so.  Drop the reference before returning success.

The commit message states it fixes a leak in sun8i_r40_tcon_tv_set_mux(),
but the patch actually modifies sun4i_tcon_init_clocks().

Looking at sun8i_r40_tcon_tv_set_mux() in the baseline, the success path
appears to fall through to the out_put_device label, which already correctly
drops the reference:

out_put_device:
        put_device(&pdev->dev);

        return ret;

Could the commit message be referencing an issue that does not exist in
this tree, or was the patch misapplied?

> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index bf405a2aa3249..b5a85738876ee 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -808,6 +808,8 @@ static int sun4i_tcon_init_clocks(struct device *dev,
>  		}
>  	}
>  
> +	put_device(&pdev->dev);

[Severity: Low]
Does this code compile? The variable pdev is undeclared in the scope of
sun4i_tcon_init_clocks(), which causes a build failure.

> +
>  	return 0;
>  }
kernel test robot Sept. 17, 2026, 1:57 p.m. UTC | #2 
Hi Wentao,

kernel test robot noticed the following build errors:

[auto build test ERROR on sunxi/sunxi/for-next]
[also build test ERROR on daeinki-drm-exynos/exynos-drm-next drm/drm-next drm-i915/for-linux-next drm-i915/for-linux-next-fixes drm-misc/drm-misc-next drm-tip/drm-tip linus/master v7.3-rc3 next-20260916]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/drm-sun4i-Fix-pdev-reference-leak-in-sun8i_r40_tcon_tv_set_mux/20260916-182412
base:   https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux.git sunxi/for-next
patch link:    https://lore.kernel.org/r/20260916182412.2091681-1-vulab%40iscas.ac.cn
patch subject: [PATCH] drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()
config: alpha-randconfig-r1306-20260917 (https://download.01.org/0day-ci/archive/20260917/202609172103.AfhCF3XZ-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 15.2.0
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260917/202609172103.AfhCF3XZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609172103.AfhCF3XZ-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/gpu/drm/sun4i/sun4i_tcon.c: In function 'sun4i_tcon_init_clocks':
>> drivers/gpu/drm/sun4i/sun4i_tcon.c:811:21: error: 'pdev' undeclared (first use in this function); did you mean 'dev'?
     811 |         put_device(&pdev->dev);
         |                     ^~~~
         |                     dev
   drivers/gpu/drm/sun4i/sun4i_tcon.c:811:21: note: each undeclared identifier is reported only once for each function it appears in


vim +811 drivers/gpu/drm/sun4i/sun4i_tcon.c

   785	
   786	static int sun4i_tcon_init_clocks(struct device *dev,
   787					  struct sun4i_tcon *tcon)
   788	{
   789		tcon->clk = devm_clk_get_enabled(dev, "ahb");
   790		if (IS_ERR(tcon->clk)) {
   791			dev_err(dev, "Couldn't get the TCON bus clock\n");
   792			return PTR_ERR(tcon->clk);
   793		}
   794	
   795		if (tcon->quirks->has_channel_0) {
   796			tcon->sclk0 = devm_clk_get_enabled(dev, "tcon-ch0");
   797			if (IS_ERR(tcon->sclk0)) {
   798				dev_err(dev, "Couldn't get the TCON channel 0 clock\n");
   799				return PTR_ERR(tcon->sclk0);
   800			}
   801		}
   802	
   803		if (tcon->quirks->has_channel_1) {
   804			tcon->sclk1 = devm_clk_get(dev, "tcon-ch1");
   805			if (IS_ERR(tcon->sclk1)) {
   806				dev_err(dev, "Couldn't get the TCON channel 1 clock\n");
   807				return PTR_ERR(tcon->sclk1);
   808			}
   809		}
   810	
 > 811		put_device(&pdev->dev);
   812	
   813		return 0;
   814	}
   815	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
kernel test robot Sept. 17, 2026, 8:29 p.m. UTC | #3 
Hi Wentao,

kernel test robot noticed the following build errors:

[auto build test ERROR on sunxi/sunxi/for-next]
[also build test ERROR on daeinki-drm-exynos/exynos-drm-next drm/drm-next drm-i915/for-linux-next drm-i915/for-linux-next-fixes drm-misc/drm-misc-next drm-tip/drm-tip linus/master v7.3-rc3 next-20260916]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/drm-sun4i-Fix-pdev-reference-leak-in-sun8i_r40_tcon_tv_set_mux/20260916-182412
base:   https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux.git sunxi/for-next
patch link:    https://lore.kernel.org/r/20260916182412.2091681-1-vulab%40iscas.ac.cn
patch subject: [PATCH] drm/sun4i: Fix pdev reference leak in sun8i_r40_tcon_tv_set_mux()
config: arm-defconfig (https://download.01.org/0day-ci/archive/20260918/202609180443.vTkwAZL6-lkp@intel.com/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 7252edd9aa82ef1c570ff6694ef7f4763a8a5d2f)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260918/202609180443.vTkwAZL6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609180443.vTkwAZL6-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/sun4i/sun4i_tcon.c:811:14: error: use of undeclared identifier 'pdev'; did you mean 'dev'?
     811 |         put_device(&pdev->dev);
         |                     ^~~~
         |                     dev
   drivers/gpu/drm/sun4i/sun4i_tcon.c:786:50: note: 'dev' declared here
     786 | static int sun4i_tcon_init_clocks(struct device *dev,
         |                                                  ^
>> drivers/gpu/drm/sun4i/sun4i_tcon.c:811:20: error: no member named 'dev' in 'struct device'
     811 |         put_device(&pdev->dev);
         |                     ~~~~  ^
   2 errors generated.


vim +811 drivers/gpu/drm/sun4i/sun4i_tcon.c

   785	
   786	static int sun4i_tcon_init_clocks(struct device *dev,
   787					  struct sun4i_tcon *tcon)
   788	{
   789		tcon->clk = devm_clk_get_enabled(dev, "ahb");
   790		if (IS_ERR(tcon->clk)) {
   791			dev_err(dev, "Couldn't get the TCON bus clock\n");
   792			return PTR_ERR(tcon->clk);
   793		}
   794	
   795		if (tcon->quirks->has_channel_0) {
   796			tcon->sclk0 = devm_clk_get_enabled(dev, "tcon-ch0");
   797			if (IS_ERR(tcon->sclk0)) {
   798				dev_err(dev, "Couldn't get the TCON channel 0 clock\n");
   799				return PTR_ERR(tcon->sclk0);
   800			}
   801		}
   802	
   803		if (tcon->quirks->has_channel_1) {
   804			tcon->sclk1 = devm_clk_get(dev, "tcon-ch1");
   805			if (IS_ERR(tcon->sclk1)) {
   806				dev_err(dev, "Couldn't get the TCON channel 1 clock\n");
   807				return PTR_ERR(tcon->sclk1);
   808			}
   809		}
   810	
 > 811		put_device(&pdev->dev);
   812	
   813		return 0;
   814	}
   815	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
diff mbox series

Patch

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 960e83c8291d..07350361fc4b 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -1444,6 +1444,8 @@  static int sun8i_r40_tcon_tv_set_mux(struct sun4i_tcon *tcon,
 		}
 	}
 
+	put_device(&pdev->dev);
+
 	return 0;
 }