Re: [PATCH v3] drm/exynos: enable fimd clocks in probe before accessing fimd registers

Hi Rahul,

On 22 May 2014 19:41, Rahul Sharma rahul.sharma@samsung.com wrote:

Fimd probe is accessing fimd Registers without enabling the fimd gate clocks. If FIMD clocks are kept disabled in Uboot or disbaled during kernel boottime, the system hangs during boottime.

This issue got surfaced when verifying with sysmmu enabled. Probe of fimd Sysmmu enables the master clock before accessing sysmmu regs and then disables. Later fimd probe tries to read the register without enabling the clock which is wrong and hangs the system.

Signed-off-by: Rahul Sharma Rahul.Sharma@samsung.com

drivers/gpu/drm/exynos/exynos_drm_fimd.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index bd30d0c..38b77ed 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -898,16 +898,31 @@ static int fimd_bind(struct device *dev, struct device *master, void *data) { struct fimd_context *ctx = fimd_manager.ctx; struct drm_device *drm_dev = data;

•   int win;
  

•   int win, ret;
  
    fimd_mgr_initialize(&fimd_manager, drm_dev);
    exynos_drm_crtc_create(&fimd_manager);
    if (ctx->display)
            exynos_drm_create_enc_conn(drm_dev, ctx->display);
  
  

•   ret = clk_prepare_enable(ctx->bus_clk);
  

•   if (ret) {
  

•           dev_err(dev, "bus clock enable failed.\n");
  

•           return ret;
  

•   }
  

•   ret = clk_prepare_enable(ctx->lcd_clk);
  

•   if (ret) {
  

•           dev_err(dev, "lcd clock enable failed.\n");
  

Add clk_disable_unprepare(ctx->bus_clk) before returning on error.

•           return ret;
  

•   }
  

•   for (win = 0; win < WINDOWS_NR; win++)
            fimd_clear_win(ctx, win);
  
  

•   clk_disable_unprepare(ctx->lcd_clk);
  

•   clk_disable_unprepare(ctx->bus_clk);
  

•   return 0;
  
  

}

1.7.9.5