mtd: spi-nor: improve wait-till-ready timeout loop

There are a few small issues with the timeout loop in
spi_nor_wait_till_ready():

 * The first operation should not be a reschedule; we should check the
   status register at least once to see if we're complete!

 * We should check the status register one last time after declaring the
   deadline has passed, to prevent a premature timeout error (this is
   theoretically possible if we sleep for a long time after the previous
   status register check).

 * Add an error message, so it's obvious if we ever hit a timeout.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <shijie.huang@intel.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
This commit is contained in:
Brian Norris 2014-11-05 02:32:03 -08:00
parent 05a221bb1f
commit a95ce92e4b
1 changed files with 9 additions and 4 deletions

View File

@ -202,19 +202,24 @@ static int spi_nor_ready(struct spi_nor *nor)
static int spi_nor_wait_till_ready(struct spi_nor *nor)
{
unsigned long deadline;
int ret;
int timeout = 0, ret;
deadline = jiffies + MAX_READY_WAIT_JIFFIES;
do {
cond_resched();
while (!timeout) {
if (time_after_eq(jiffies, deadline))
timeout = 1;
ret = spi_nor_ready(nor);
if (ret < 0)
return ret;
if (ret)
return 0;
} while (!time_after_eq(jiffies, deadline));
cond_resched();
}
dev_err(nor->dev, "flash operation timed out\n");
return -ETIMEDOUT;
}