[PATCH 5.10 376/406] mtd: rawnand: brcmnand: Fix potential false time out warning

Greg Kroah-Hartman
2023-09-17T19:41:48Z

From: William Zhang <william.zhang@broadcom.com>

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>
---
drivers/mtd/nand/raw/brcmnand/brcmnand.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1040,6 +1040,14 @@ static int bcmnand_ctrl_poll_status(stru
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);