[PATCH 03/12] mtd: rawnand: brcmnand: Fix crash during the panic_write

William Zhang
2023-06-06T23:14:43Z

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During the panic write path to execute another nand command, if
there is a pending command, we should wait for the command instead of
calling BUG_ON so we don't crash while 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>
---

drivers/mtd/nand/raw/brcmnand/brcmnand.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index b6346a8b9833..20832857c4aa 100644
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1608,7 +1608,17 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)

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);
--
2.37.3