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()."

[[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]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions