On Fri, Aug 17, 2018 at 07:54:09PM +0300, Sergei Shtylyov wrote:
> I have encountered an interrupt storm during the eMMC chip probing (and
> the chip finally didn't get detected). It turned out  that U-Boot  left
> the SDHI DMA interrupts enabled while the Linux  driver didn't use those.
> Masking those interrupts in renesas_sdhi_internal_dmac_request_dma() gets
> rid  of both  issues...
> 
> Signed-off-by: Sergei Shtylyov <[email protected]>

Thanks for fixing this issue.

> 
> ---
> The patch is against Ulf Hansson's 'mmc.git' repo's 'fixes' branch.
> 
>  drivers/mmc/host/renesas_sdhi_internal_dmac.c |   11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> Index: mmc/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> ===================================================================
> --- mmc.orig/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> +++ mmc/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> @@ -51,10 +51,12 @@
>  #define INFO1_CLEAR          0
>  #define INFO1_DTRANEND1              BIT(17)
>  #define INFO1_DTRANEND0              BIT(16)
> +#define INFO1_RESERVED_BITS  GENMASK_ULL(32, 0)

31?

Also, RESERVED_BITS is not quite proper. Not all of those bits are
reserved. Maybe CLEAR_MASK?

>  /* DM_CM_INFO2 and DM_CM_INFO2_MASK */
>  #define INFO2_DTRANERR1              BIT(17)
>  #define INFO2_DTRANERR0              BIT(16)
> +#define INFO2_RESERVED_BITS  GENMASK_ULL(32, 0)

Same as above. Maybe we even need one define only?

> +     /*
> +      * We don't use the DMA interrupts,  but they might have been enabled
> +      * by a bootloader,  so mask them to avoid an interrupt storm...
> +      */

Two spaces after ',' looks odd to me. Also, no need for "..."
I'd even think with a name like CLEAR_MASK, the comment could even go.

> +     renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1_MASK,
> +                                         INFO1_RESERVED_BITS);
> +     renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO2_MASK,
> +                                         INFO2_RESERVED_BITS);

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