mtd: Blackfin NFC: fix nand busy detection

The IRQSTAT register is a W1C register used by the interrupt handler and
may have its BUSY bit changed.  This makes it somewhat unreliable for the
polling devready function.  So switch it over to use the BUSY bit in the
STAT register that always reflects the current state of the hardware.

This fixes driver hangs seen when the NAND flash is under heavy system
load (like I/O benchmarks).

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Barry Song 2010-08-05 11:07:38 -04:00 committed by David Woodhouse
parent 44299179c0
commit d2350c2ab5

View File

@ -215,9 +215,9 @@ static void bf5xx_nand_hwcontrol(struct mtd_info *mtd, int cmd,
*/
static int bf5xx_nand_devready(struct mtd_info *mtd)
{
unsigned short val = bfin_read_NFC_IRQSTAT();
unsigned short val = bfin_read_NFC_STAT();
if ((val & NBUSYIRQ) == NBUSYIRQ)
if ((val & NBUSY) == NBUSY)
return 1;
else
return 0;