Re: [PATCH v3 3/5] mtd: rawnand: brcmnand: Fix crash during the panic_write

William Zhang
2023-07-05T00:40:52Z

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Hi Miquel,

On 07/04/2023 08:26 AM, Miquel Raynal wrote:
> Hi William,
>
> william.zhang@broadcom.com wrote on Tue, 27 Jun 2023 12:37:36 -0700:
>
>> 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")
>
> The Fixes tag looks wrong.
>
The brcmnand_send_cmd function and BUG_ON line were added by this commit
and the function didn't changed much since then. Not sure why you think
it is wrong?

>> 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>
>> ---
>>
>> Changes in v3: None
>> Changes in v2: None
>>
>> 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 37c2c7cfa00e..ea03104692bf 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);
>
>
> Thanks,
> Miquèl