5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: William Zhang <william.zhang@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Reviewed-by: Kursad Oney <kursad.oney@xxxxxxxxxxxx> Reviewed-by: Kamal Dasu <kamal.dasu@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> Link: https://lore.kernel.org/linux-mtd/20230706182909.79151-4-william.zhang@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -1563,7 +1563,17 @@ 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);