Re: [PATCH v2 1/2] [media] s5p-jpeg: Fix modification sequence of interrupt enable register

[Jacek Anaszewski <j.anaszewski@samsung.com>]

Hi Tony,

On 12/19/2014 08:37 AM, Tony K Nadackal wrote:
> Fix the bug in modifying the interrupt enable register.

For Exynos4 this was not a bug as there are only five bit fields
used in the EXYNOS4_INT_EN_REG - all of them enable related
interrupt signal and EXYNOS4_INT_EN_ALL value is 0x1f which
just sets these bit fields to 1.

If for Exynos7 there are other bit fields in this register
and it has to be read prior setting to find out current
state then I'd parametrize this function with version argument
as you do it in the patch adding support for Exynos7, but
for Exynos4 case I'd left the behaviour as it is currenlty, i.e.
avoid reading the register and do it only for Exynos7 case.
Effectively, this patch is not required, as it doesn't fix
anything but adds redundant call to readl.

> Signed-off-by: Tony K Nadackal <tony.kn@samsung.com>
> ---
>   drivers/media/platform/s5p-jpeg/jpeg-hw-exynos4.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/s5p-jpeg/jpeg-hw-exynos4.c b/drivers/media/platform/s5p-jpeg/jpeg-hw-exynos4.c
> index e53f13a..a61ff7e 100644
> --- a/drivers/media/platform/s5p-jpeg/jpeg-hw-exynos4.c
> +++ b/drivers/media/platform/s5p-jpeg/jpeg-hw-exynos4.c
> @@ -155,7 +155,10 @@ void exynos4_jpeg_set_enc_out_fmt(void __iomem *base, unsigned int out_fmt)
>
>   void exynos4_jpeg_set_interrupt(void __iomem *base)
>   {
> -	writel(EXYNOS4_INT_EN_ALL, base + EXYNOS4_INT_EN_REG);
> +	unsigned int reg;
> +
> +	reg = readl(base + EXYNOS4_INT_EN_REG) & ~EXYNOS4_INT_EN_MASK;
> +	writel(reg | EXYNOS4_INT_EN_ALL, base + EXYNOS4_INT_EN_REG);
>   }
>
>   unsigned int exynos4_jpeg_get_int_status(void __iomem *base)
>


-- 
Best Regards,
Jacek Anaszewski