[PATCH 5.10 374/406] mtd: rawnand: brcmnand: Fix crash during the panic_write

Greg Kroah-Hartman
2023-09-17T19:41:47Z

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

commit e66dd317194daae0475fe9e5577c80aa97f16cb9 upstream.

When executing a NAND command within the panic write path, wait for any
pending command instead of calling BUG_ON to avoid crashing while
already crashing.

Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Kursad Oney <kursad.oney@broadcom.com>
Reviewed-by: Kamal Dasu <kamal.dasu@broadcom.com>
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230706182909.79151-4-william.zhang@broadcom.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mtd/nand/raw/brcmnand/brcmnand.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1543,7 +1543,17 @@ static void brcmnand_send_cmd(struct brc

dev_dbg(ctrl->dev, "send native cmd %d addr 0x%llx\n", cmd, cmd_addr);

- BUG_ON(ctrl->cmd_pending != 0);
+ /*
+ * If we came here through _panic_write and there is a pending
+ * command, try to wait for it. If it times out, rather than
+ * hitting BUG_ON, just return so we don't crash while crashing.
+ */
+ if (oops_in_progress) {
+ if (ctrl->cmd_pending &&
+ bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY, NAND_CTRL_RDY, 0))
+ return;
+ } else
+ BUG_ON(ctrl->cmd_pending != 0);
ctrl->cmd_pending = cmd;

ret = bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);