Re: [PATCH v3] drm/exynos: enable FIMD clocks

On 1 April 2013 14:13, Vikas Sajjan vikas.sajjan@linaro.org wrote:

While migrating to common clock framework (CCF), found that the FIMD clocks

s/found/we found/

were pulled down by the CCF. If CCF finds any clock(s) which has NOT been claimed by any of the drivers, then such clock(s) are PULLed low by CCF.

By calling clk_prepare_enable() for FIMD clocks fixes the issue.

s/By calling/Calling/

and

s/the/this

this patch also replaces clk_disable() with clk_disable_unprepare()

s/this/This

during exit.

Sorry but your log doesn't say what you are doing. You are just adding relevant calls to clk_prepare/unprepare() before calling clk_enable/disable.

Signed-off-by: Vikas Sajjan vikas.sajjan@linaro.org

Changes since v2: - moved clk_prepare_enable() and clk_disable_unprepare() from fimd_probe() to fimd_clock() as suggested by Inki Dae inki.dae@samsung.com Changes since v1: - added error checking for clk_prepare_enable() and also replaced clk_disable() with clk_disable_unprepare() during exit.

---

drivers/gpu/drm/exynos/exynos_drm_fimd.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index 9537761..f2400c8 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -799,18 +799,18 @@ static int fimd_clock(struct fimd_context *ctx, bool enable) if (enable) { int ret;

•           ret = clk_enable(ctx->bus_clk);
  

•           ret = clk_prepare_enable(ctx->bus_clk);
            if (ret < 0)
                    return ret;
  
  

•           ret = clk_enable(ctx->lcd_clk);
  

•           ret = clk_prepare_enable(ctx->lcd_clk);
            if  (ret < 0) {
  

•                   clk_disable(ctx->bus_clk);
  

•                   clk_disable_unprepare(ctx->bus_clk);
                    return ret;
            }
    } else {
  

•           clk_disable(ctx->lcd_clk);
  

•           clk_disable(ctx->bus_clk);
  

•           clk_disable_unprepare(ctx->lcd_clk);
  

•           clk_disable_unprepare(ctx->bus_clk);
    }
  
    return 0;
  

@@ -981,8 +981,8 @@ static int fimd_remove(struct platform_device *pdev) if (ctx->suspended) goto out;

•   clk_disable(ctx->lcd_clk);
  

•   clk_disable(ctx->bus_clk);
  

•   clk_disable_unprepare(ctx->lcd_clk);
  

•   clk_disable_unprepare(ctx->bus_clk);
  

You are doing things at the right place but i have a suggestion. Are you doing anything in your clk_prepare() atleast for this device? Probably not.

If not, then its better to call clk_prepare/unprepare only once at probe/remove and keep clk_enable/disable calls as is.

-- viresh