Commit a95ce92e authored Nov 05, 2014 by Brian Norris

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>

parent 05a221bb

drivers/mtd/spi-nor/spi-nor.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -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;
		}