diff options
| author | Yusuke Goda <yusuke.goda.sx@renesas.com> | 2010-09-09 16:37:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-09-09 18:57:23 -0700 |
| commit | b78d6c5f51935ba89df8db33a57bacb547aa7325 (patch) | |
| tree | 7cd4c5bb1d9f7d5f3c0815705ce8d52d4c81463a /drivers | |
| parent | 31583bb0cf6cc40f2a468a4d2f3b9cbefd24f891 (diff) | |
tmio_mmc: don't clear unhandled pending interrupts
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()."
[matt@console-pimps.org: rewrote changelog]
Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Acked-by: Magnus Damm <damm@opensource.se>"
Tested-by: Arnd Hannemann <arnd@arndnet.de>"
Acked-by: Ian Molton <ian@mnementh.co.uk>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | 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 64f7d5dfc10..79446047ee7 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -82,10 +82,7 @@ #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) |