From: Yusuke Goda <[email protected]> commit b78d6c5f51935ba89df8db33a57bacb547aa7325 upstream.
Previously, it was possible for ack_mmc_irqs() to clear pending interrupt bits in the CTL_STATUS register, even though the interrupt handler had not been called. This was because of a race that existed when doing a read-modify-write sequence on CTL_STATUS. After the read step in this sequence, if an interrupt occurred (causing one of the bits in CTL_STATUS to be set) the write step would inadvertently clear it. Observed with the TMIO_STAT_RXRDY bit together with CMD53 on AR6002 and BCM4318 SDIO cards in polled mode. This patch eliminates this race by only writing to CTL_STATUS and clearing the interrupts that were passed as an argument to ack_mmc_irqs()." [[email protected]: rewrote changelog] Signed-off-by: Yusuke Goda <[email protected]> Acked-by: Magnus Damm <[email protected]>" Tested-by: Arnd Hannemann <[email protected]>" Acked-by: Ian Molton <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Samuel Ortiz <[email protected]> Cc: Paul Mundt <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- drivers/mmc/host/tmio_mmc.h | 5 +---- 1 files changed, 1 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index dafecfb..1836ed9 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -80,10 +80,7 @@ #define ack_mmc_irqs(host, i) \ do { \ - u32 mask;\ - mask = sd_ctrl_read32((host), CTL_STATUS); \ - mask &= ~((i) & TMIO_MASK_IRQ); \ - sd_ctrl_write32((host), CTL_STATUS, mask); \ + sd_ctrl_write32((host), CTL_STATUS, ~(i)); \ } while (0) -- 1.7.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
