Re: [PATCH] mmc: omap_hsmmc: clear status flags before starting anew command

[Balaji T K]

On Saturday 29 June 2013 11:55 AM, Francesco Lavra wrote:
> Commit 1f6b9fa40e76fffaaa0b3bd6a0bfdcf1cdc06efa consolidated writes to
> the STAT register in one location, moving them from omap_hsmmc_do_irq()
> to omap_hsmmc_irq(). This move has the unwanted side effect that the
> controller status flags are potentially cleared after a new command has
> been started as a consequence of reading the previous status flags.
> This means that if the new command changes the status flags before the
> IRQ routine returns, those flags may be cleared without handling the
> event which asserted them, and thus missing the event.
> Move the writing of the STAT register back in omap_hsmmc_do_irq(),
> before handling the status flags which generated the interrupt.
>
> Signed-off-by: Francesco Lavra <francescolavra.fl@xxxxxxxxx>

Reviewed and Tested-by: Balaji T K <balajitk@xxxxxx>

> ---
>   drivers/mmc/host/omap_hsmmc.c |    2 +-
>   1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index eccedc7..301cb7e 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -1041,6 +1041,7 @@ static void omap_hsmmc_do_irq(struct omap_hsmmc_host *host, int status)
>   		}
>   	}
>
> +	OMAP_HSMMC_WRITE(host->base, STAT, status);
>   	if (end_cmd || ((status & CC_EN) && host->cmd))
>   		omap_hsmmc_cmd_done(host, host->cmd);
>   	if ((end_trans || (status & TC_EN)) && host->mrq)
> @@ -1060,7 +1061,6 @@ static irqreturn_t omap_hsmmc_irq(int irq, void *dev_id)
>   		omap_hsmmc_do_irq(host, status);
>
>   		/* Flush posted write */
> -		OMAP_HSMMC_WRITE(host->base, STAT, status);
>   		status = OMAP_HSMMC_READ(host->base, STAT);
>   	}
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