| Message ID | f15bc57648a00e7c99f943903468a04639d50596.1628241097.git.christophe.jaillet@wanadoo.fr |
|---|---|
| State | Accepted |
| Commit | 6977cc89c87506ff17e6c05f0e37f46752256e82 |
| Headers | show |
| Series | drm/msm/dsi: Fix some reference counted resource leaks | expand |
On 06/08/2021 12:15, Christophe JAILLET wrote: > 'of_find_device_by_node()' takes a reference that must be released when > not needed anymore. > This is expected to be done in 'dsi_destroy()'. > > However, there are 2 issues in 'dsi_get_phy()'. > > First, if 'of_find_device_by_node()' succeeds but 'platform_get_drvdata()' > returns NULL, 'msm_dsi->phy_dev' will still be NULL, and the reference > won't be released in 'dsi_destroy()'. > > Secondly, as 'of_find_device_by_node()' already takes a reference, there is > no need for an additional 'get_device()'. > > Move the assignment to 'msm_dsi->phy_dev' a few lines above and remove the > unneeded 'get_device()' to solve both issues. > > Fixes: ec31abf6684e ("drm/msm/dsi: Separate PHY to another platform device") > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > --- > Review carefully, management of reference counted resources is sometimes > tricky. > --- > drivers/gpu/drm/msm/dsi/dsi.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c > index 75afc12a7b25..29d11f1cb79b 100644 > --- a/drivers/gpu/drm/msm/dsi/dsi.c > +++ b/drivers/gpu/drm/msm/dsi/dsi.c > @@ -26,8 +26,10 @@ static int dsi_get_phy(struct msm_dsi *msm_dsi) > } > > phy_pdev = of_find_device_by_node(phy_node); > - if (phy_pdev) > + if (phy_pdev) { > msm_dsi->phy = platform_get_drvdata(phy_pdev); > + msm_dsi->phy_dev = &phy_pdev->dev; > + } > > of_node_put(phy_node); > > @@ -36,8 +38,6 @@ static int dsi_get_phy(struct msm_dsi *msm_dsi) > return -EPROBE_DEFER; > } > > - msm_dsi->phy_dev = get_device(&phy_pdev->dev); > - > return 0; > } > > -- With best wishes Dmitry
diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c index 75afc12a7b25..29d11f1cb79b 100644 --- a/drivers/gpu/drm/msm/dsi/dsi.c +++ b/drivers/gpu/drm/msm/dsi/dsi.c @@ -26,8 +26,10 @@ static int dsi_get_phy(struct msm_dsi *msm_dsi) } phy_pdev = of_find_device_by_node(phy_node); - if (phy_pdev) + if (phy_pdev) { msm_dsi->phy = platform_get_drvdata(phy_pdev); + msm_dsi->phy_dev = &phy_pdev->dev; + } of_node_put(phy_node); @@ -36,8 +38,6 @@ static int dsi_get_phy(struct msm_dsi *msm_dsi) return -EPROBE_DEFER; } - msm_dsi->phy_dev = get_device(&phy_pdev->dev); - return 0; }
'of_find_device_by_node()' takes a reference that must be released when not needed anymore. This is expected to be done in 'dsi_destroy()'. However, there are 2 issues in 'dsi_get_phy()'. First, if 'of_find_device_by_node()' succeeds but 'platform_get_drvdata()' returns NULL, 'msm_dsi->phy_dev' will still be NULL, and the reference won't be released in 'dsi_destroy()'. Secondly, as 'of_find_device_by_node()' already takes a reference, there is no need for an additional 'get_device()'. Move the assignment to 'msm_dsi->phy_dev' a few lines above and remove the unneeded 'get_device()' to solve both issues. Fixes: ec31abf6684e ("drm/msm/dsi: Separate PHY to another platform device") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- Review carefully, management of reference counted resources is sometimes tricky. --- drivers/gpu/drm/msm/dsi/dsi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)