[PATCH 04/10] drm/exynos: Use devm_clk_get in exynos_drm_fimc.c

Sachin Kamat sachin.kamat at linaro.org
Thu Dec 27 03:04:52 PST 2012


On 27 December 2012 15:43, Inki Dae <inki.dae at samsung.com> wrote:
>
>
> 2012/12/26 Sachin Kamat <sachin.kamat at linaro.org>
>>
>>
>>
>> On Wednesday, 26 December 2012, Inki Dae <inki.dae at samsung.com> wrote:
>> >
>> >
>> > 2012/12/24 Sachin Kamat <sachin.kamat at linaro.org>
>> >>
>> >> This eliminates the need for explicit clk_put and makes the
>> >> cleanup and exit path code simpler.
>> >>
>> >> Cc: Eunchul Kim <chulspro.kim at samsung.com>
>> >> Signed-off-by: Sachin Kamat <sachin.kamat at linaro.org>
>> >> ---
>> >>  drivers/gpu/drm/exynos/exynos_drm_fimc.c |   46
>> >> ++++++-----------------------
>> >>  1 files changed, 10 insertions(+), 36 deletions(-)
>> >>
>> >> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimc.c
>> >> b/drivers/gpu/drm/exynos/exynos_drm_fimc.c
>> >> index 972aa70..c4006b8 100644
>> >> --- a/drivers/gpu/drm/exynos/exynos_drm_fimc.c
>> >> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimc.c
>> >> @@ -1739,64 +1739,50 @@ static int __devinit fimc_probe(struct
>> >> platform_device *pdev)
>> >>                 platform_get_device_id(pdev)->driver_data;
>> >>
>> >>         /* clock control */
>> >> -       ctx->sclk_fimc_clk = clk_get(dev, "sclk_fimc");
>> >> +       ctx->sclk_fimc_clk = devm_clk_get(dev, "sclk_fimc");
>> >>         if (IS_ERR(ctx->sclk_fimc_clk)) {
>> >>                 dev_err(dev, "failed to get src fimc clock.\n");
>> >>                 return PTR_ERR(ctx->sclk_fimc_clk);
>> >>         }
>> >>         clk_enable(ctx->sclk_fimc_clk);
>> >>
>> >> -       ctx->fimc_clk = clk_get(dev, "fimc");
>> >> +       ctx->fimc_clk = devm_clk_get(dev, "fimc");
>> >>         if (IS_ERR(ctx->fimc_clk)) {
>> >>                 dev_err(dev, "failed to get fimc clock.\n");
>> >>                 clk_disable(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->sclk_fimc_clk);
>> >>                 return PTR_ERR(ctx->fimc_clk);
>> >>         }
>> >>
>> >> -       ctx->wb_clk = clk_get(dev, "pxl_async0");
>> >> +       ctx->wb_clk = devm_clk_get(dev, "pxl_async0");
>> >>         if (IS_ERR(ctx->wb_clk)) {
>> >>                 dev_err(dev, "failed to get writeback a clock.\n");
>> >>                 clk_disable(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->fimc_clk);
>> >>                 return PTR_ERR(ctx->wb_clk);
>> >>         }
>> >>
>> >> -       ctx->wb_b_clk = clk_get(dev, "pxl_async1");
>> >> +       ctx->wb_b_clk = devm_clk_get(dev, "pxl_async1");
>> >>         if (IS_ERR(ctx->wb_b_clk)) {
>> >>                 dev_err(dev, "failed to get writeback b clock.\n");
>> >>                 clk_disable(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->fimc_clk);
>> >> -               clk_put(ctx->wb_clk);
>> >>                 return PTR_ERR(ctx->wb_b_clk);
>> >>         }
>> >>
>> >> -       parent_clk = clk_get(dev, ddata->parent_clk);
>> >> +       parent_clk = devm_clk_get(dev, ddata->parent_clk);
>> >>
>> >>         if (IS_ERR(parent_clk)) {
>> >>                 dev_err(dev, "failed to get parent clock.\n");
>> >>                 clk_disable(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->fimc_clk);
>> >> -               clk_put(ctx->wb_clk);
>> >> -               clk_put(ctx->wb_b_clk);
>> >>                 return PTR_ERR(parent_clk);
>> >>         }
>> >>
>> >>         if (clk_set_parent(ctx->sclk_fimc_clk, parent_clk)) {
>> >>                 dev_err(dev, "failed to set parent.\n");
>> >> -               clk_put(parent_clk);
>> >> +               devm_clk_put(dev, parent_clk);
>> >
>> > remove the above call. is there any reason that devm_clk_put should be
>> > called here?
>>
>> Devm resources are freed/released automatically only when the device
>> detaches. In the above case the clock was released explicitly (for whatever
>> reasons) earlier. Hence i have used devm call to keep the code logic same as
>> i do not know the behavior if this clock is 'put' when the device detaches
>> instead of here.
>>
>
> If probe is failed, devm resources are released by devres_release_all(). So
> that is unnecessary call. Remove it.

In this case you are right. It is not required. I will remove it.
But in the below case it is not part of cleanup, so I will keep it.
What is your opinion about it?

>
>>
>>
>> >
>> >>
>> >>                 clk_disable(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->sclk_fimc_clk);
>> >> -               clk_put(ctx->fimc_clk);
>> >> -               clk_put(ctx->wb_clk);
>> >> -               clk_put(ctx->wb_b_clk);
>> >>                 return -EINVAL;
>> >>         }
>> >>
>> >> -       clk_put(parent_clk);
>> >> +       devm_clk_put(dev, parent_clk);
>> >
>> > ditto.
>> >
>> >>
>> >>         clk_set_rate(ctx->sclk_fimc_clk, pdata->clk_rate);
>> >>
>> >>         /* resource memory */
>> >> @@ -1804,16 +1790,14 @@ static int __devinit fimc_probe(struct
>> >> platform_device *pdev)
>> >>         ctx->regs = devm_request_and_ioremap(dev, ctx->regs_res);
>> >>         if (!ctx->regs) {
>> >>                 dev_err(dev, "failed to map registers.\n");
>> >> -               ret = -ENXIO;
>> >> -               goto err_clk;
>> >> +               return -ENXIO;
>> >>         }
>> >>
>> >>         /* resource irq */
>> >>         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>> >>         if (!res) {
>> >>                 dev_err(dev, "failed to request irq resource.\n");
>> >> -               ret = -ENOENT;
>> >> -               goto err_clk;
>> >> +               return -ENOENT;
>> >>         }
>> >>
>> >>         ctx->irq = res->start;
>> >> @@ -1821,7 +1805,7 @@ static int __devinit fimc_probe(struct
>> >> platform_device *pdev)
>> >>                 IRQF_ONESHOT, "drm_fimc", ctx);
>> >>         if (ret < 0) {
>> >>                 dev_err(dev, "failed to request irq.\n");
>> >> -               goto err_clk;
>> >> +               return ret;
>> >>         }
>> >>
>> >>         /* context initailization */
>> >> @@ -1867,11 +1851,6 @@ err_ippdrv_register:
>> >>         pm_runtime_disable(dev);
>> >>  err_get_irq:
>> >>         free_irq(ctx->irq, ctx);
>> >> -err_clk:
>> >> -       clk_put(ctx->sclk_fimc_clk);
>> >> -       clk_put(ctx->fimc_clk);
>> >> -       clk_put(ctx->wb_clk);
>> >> -       clk_put(ctx->wb_b_clk);
>> >>
>> >>         return ret;
>> >>  }
>> >> @@ -1891,11 +1870,6 @@ static int __devexit fimc_remove(struct
>> >> platform_device *pdev)
>> >>
>> >>         free_irq(ctx->irq, ctx);
>> >>
>> >> -       clk_put(ctx->sclk_fimc_clk);
>> >> -       clk_put(ctx->fimc_clk);
>> >> -       clk_put(ctx->wb_clk);
>> >> -       clk_put(ctx->wb_b_clk);
>> >> -
>> >>         return 0;
>> >>  }
>> >>
>> >> --
>> >> 1.7.4.1
>> >>
>> >> _______________________________________________
>> >> dri-devel mailing list
>> >> dri-devel at lists.freedesktop.org
>> >> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>> >
>> >
>>
>> --
>> With warm regards,
>> Sachin
>>
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
>



-- 
With warm regards,
Sachin


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