mtd: rawnand: brcmnand: Fix potential false time out warning

commit 9cc0a598b944816f2968baf2631757f22721b996 upstream.

If system is busy during the command status polling function, the driver
may not get the chance to poll the status register till the end of time
out and return the premature status.  Do a final check after time out
happens to ensure reading the correct status.

Fixes: 9d2ee0a60b8b ("mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program")
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230706182909.79151-3-william.zhang@broadcom.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index 414653a2a1f7e236515983d3e84ea9da0906af0d..c1afadb50eeccb73885083db9eecd6c2def18712 100644 (file)
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1043,6 +1043,14 @@ static int bcmnand_ctrl_poll_status(struct brcmnand_controller *ctrl,
                cpu_relax();
        } while (time_after(limit, jiffies));
 
+       /*
+        * do a final check after time out in case the CPU was busy and the driver
+        * did not get enough time to perform the polling to avoid false alarms
+        */
+       val = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
+       if ((val & mask) == expected_val)
+               return 0;
+
        dev_warn(ctrl->dev, "timeout on status poll (expected %x got %x)\n",
                 expected_val, val & mask);