| Message ID | 20250213112801.1611525-1-mordan@ispras.ru (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] gpu: cdns-mhdp8546: fix call balance of mhdp->clk handling routines | expand |
On Thu, Feb 13, 2025 at 02:28:01PM +0300, Vitalii Mordan wrote: > If the clock mhdp->clk was not enabled in cdns_mhdp_probe(), it should not > be disabled in any path. > > Use the devm_clk_get_enabled() helper function to ensure proper call > balance for mhdp->clk. > > Found by Linux Verification Center (linuxtesting.org) with Klever. > > Fixes: fb43aa0acdfd ("drm: bridge: Add support for Cadence MHDP8546 DPI/DP bridge") Please describe, what is the actual issue that is being fixed. In other words, which path leads to unbalanced enable or disable call. Otherwise it seems to be a valid patch, not qualified as a fix. > Signed-off-by: Vitalii Mordan <mordan@ispras.ru> > --- > v2: Use devm_clk_get_enabled() helper function, as per Dmitry Baryshkov's > request. > > drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c > index d081850e3c03..d4e4f484cbe5 100644 > --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c > @@ -2463,9 +2463,9 @@ static int cdns_mhdp_probe(struct platform_device *pdev) > if (!mhdp) > return -ENOMEM; > > - clk = devm_clk_get(dev, NULL); > + clk = devm_clk_get_enabled(dev, NULL); > if (IS_ERR(clk)) { > - dev_err(dev, "couldn't get clk: %ld\n", PTR_ERR(clk)); > + dev_err(dev, "couldn't get and enable clk: %ld\n", PTR_ERR(clk)); > return PTR_ERR(clk); > } > > @@ -2504,14 +2504,12 @@ static int cdns_mhdp_probe(struct platform_device *pdev) > > mhdp->info = of_device_get_match_data(dev); > > - clk_prepare_enable(clk); > - > pm_runtime_enable(dev); > ret = pm_runtime_resume_and_get(dev); > if (ret < 0) { > dev_err(dev, "pm_runtime_resume_and_get failed\n"); > pm_runtime_disable(dev); > - goto clk_disable; > + return ret; > } > > if (mhdp->info && mhdp->info->ops && mhdp->info->ops->init) { > @@ -2590,8 +2588,6 @@ static int cdns_mhdp_probe(struct platform_device *pdev) > runtime_put: > pm_runtime_put_sync(dev); > pm_runtime_disable(dev); > -clk_disable: > - clk_disable_unprepare(mhdp->clk); > > return ret; > } > @@ -2632,8 +2628,6 @@ static void cdns_mhdp_remove(struct platform_device *pdev) > cancel_work_sync(&mhdp->modeset_retry_work); > flush_work(&mhdp->hpd_work); > /* Ignoring mhdp->hdcp.check_work and mhdp->hdcp.prop_work here. */ > - > - clk_disable_unprepare(mhdp->clk); > } > > static const struct of_device_id mhdp_ids[] = { > -- > 2.25.1 >
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index d081850e3c03..d4e4f484cbe5 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -2463,9 +2463,9 @@ static int cdns_mhdp_probe(struct platform_device *pdev) if (!mhdp) return -ENOMEM; - clk = devm_clk_get(dev, NULL); + clk = devm_clk_get_enabled(dev, NULL); if (IS_ERR(clk)) { - dev_err(dev, "couldn't get clk: %ld\n", PTR_ERR(clk)); + dev_err(dev, "couldn't get and enable clk: %ld\n", PTR_ERR(clk)); return PTR_ERR(clk); } @@ -2504,14 +2504,12 @@ static int cdns_mhdp_probe(struct platform_device *pdev) mhdp->info = of_device_get_match_data(dev); - clk_prepare_enable(clk); - pm_runtime_enable(dev); ret = pm_runtime_resume_and_get(dev); if (ret < 0) { dev_err(dev, "pm_runtime_resume_and_get failed\n"); pm_runtime_disable(dev); - goto clk_disable; + return ret; } if (mhdp->info && mhdp->info->ops && mhdp->info->ops->init) { @@ -2590,8 +2588,6 @@ static int cdns_mhdp_probe(struct platform_device *pdev) runtime_put: pm_runtime_put_sync(dev); pm_runtime_disable(dev); -clk_disable: - clk_disable_unprepare(mhdp->clk); return ret; } @@ -2632,8 +2628,6 @@ static void cdns_mhdp_remove(struct platform_device *pdev) cancel_work_sync(&mhdp->modeset_retry_work); flush_work(&mhdp->hpd_work); /* Ignoring mhdp->hdcp.check_work and mhdp->hdcp.prop_work here. */ - - clk_disable_unprepare(mhdp->clk); } static const struct of_device_id mhdp_ids[] = {
If the clock mhdp->clk was not enabled in cdns_mhdp_probe(), it should not be disabled in any path. Use the devm_clk_get_enabled() helper function to ensure proper call balance for mhdp->clk. Found by Linux Verification Center (linuxtesting.org) with Klever. Fixes: fb43aa0acdfd ("drm: bridge: Add support for Cadence MHDP8546 DPI/DP bridge") Signed-off-by: Vitalii Mordan <mordan@ispras.ru> --- v2: Use devm_clk_get_enabled() helper function, as per Dmitry Baryshkov's request. drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)