mmc: omap_hsmmc: clear status flags before starting a new command

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@gmail.com>
Reviewed-and-Tested-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index c937ffc61bc24eab03e7bed729d05c6df7395452..6ac63df645c405b0bd6586c7f8d993d940f8c1af 100644 (file)
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1042,6 +1042,7 @@ 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)
@@ -1061,7 +1062,6 @@ 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);
        }