linux/drivers/mmc
Yusuke Goda b78d6c5f51 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>
2010-09-09 18:57:23 -07:00
..
card mmc_test: fix large memory allocation 2010-08-12 08:43:31 -07:00
core mmc: avoid getting CID on SDIO-only cards 2010-09-09 18:57:22 -07:00
host tmio_mmc: don't clear unhandled pending interrupts 2010-09-09 18:57:23 -07:00
Kconfig mmc: explicitly mention SDIO support in Kconfig 2008-10-12 11:04:36 +02:00
Makefile mmc: Move core functions to subdir 2007-05-01 13:04:18 +02:00