while the imxfb driver blanks the screen. The clock supply to the framebuffer controller is disabled. The same callback to disable the fb is, however, also used the remove and shutdown hooks of the imxfb platform driver. This means that the imxfb driver can run into a WARN in clock_disable while unloading or rebooting, if the screen is blanked previously, since the same clock will be than eventually disabled multiple times. This patch adds a flag to make sure that the clock will only be disabled, if it was not already disabled before. The remove or shutdown callbacks in the imxfb platform driver call imxfb_disable_controller to disable the hardware, Signed-off-by: Luotao Fu <l.fu@xxxxxxxxxxxxxx> --- drivers/video/imxfb.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c index 17c6b5f..6ef9817 100644 --- a/drivers/video/imxfb.c +++ b/drivers/video/imxfb.c @@ -35,6 +35,7 @@ #include <mach/imxfb.h> #include <mach/hardware.h> +#include <mach/clock.h> /* * Complain if VAR is out of range. @@ -176,6 +177,7 @@ struct imxfb_info { struct imx_fb_videomode *mode; int num_modes; + bool fbclk_disabled; void (*lcd_power)(int); void (*backlight_power)(int); @@ -466,6 +468,7 @@ static void imxfb_enable_controller(struct imxfb_info *fbi) writel(RMCR_LCDC_EN, fbi->regs + LCDC_RMCR); clk_enable(fbi->clk); + fbi->fbclk_disabled = 0; if (fbi->backlight_power) fbi->backlight_power(1); @@ -482,7 +485,10 @@ static void imxfb_disable_controller(struct imxfb_info *fbi) if (fbi->lcd_power) fbi->lcd_power(0); - clk_disable(fbi->clk); + if (!fbi->fbclk_disabled) { + fbi->fbclk_disabled = 1; + clk_disable(fbi->clk); + } writel(0, fbi->regs + LCDC_RMCR); } @@ -863,7 +869,10 @@ static int __devexit imxfb_remove(struct platform_device *pdev) iounmap(fbi->regs); release_mem_region(res->start, resource_size(res)); - clk_disable(fbi->clk); + + if (!fbi->fbclk_disabled) + clk_disable(fbi->clk); + clk_put(fbi->clk); platform_set_drvdata(pdev, NULL); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html