RE: [PATCH v2 2/7] mtd: rawnand: brcmnand: Fix potential false time out warning

[William Zhang <william.zhang@broadcom.com>]

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> -----Original Message-----
> From: Linus Walleij <linus.walleij@linaro.org>
> Sent: Monday, September 16, 2024 2:59 AM
> To: u-boot@lists.denx.de; Dario Binacchi
> <dario.binacchi@amarulasolutions.com>; Michael Trimarchi
> <michael@amarulasolutions.com>; Anand Gore
> <anand.gore@broadcom.com>; William Zhang
> <william.zhang@broadcom.com>; Kursad Oney
> <kursad.oney@broadcom.com>; Philippe Reynes
> <philippe.reynes@softathome.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>; Florian Fainelli
> <florian.fainelli@broadcom.com>; Miquel Raynal
> <miquel.raynal@bootlin.com>
> Subject: [PATCH v2 2/7] mtd: rawnand: brcmnand: Fix potential false time
> out warning
>
> From: William Zhang <william.zhang@broadcom.com>
>
> Backport from the Linux kernel:
> commit 9cc0a598b944816f2968baf2631757f22721b996
> "mtd: rawnand: brcmnand: Fix potential false time out warning"
>
> 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.
>
> Signed-off-by: William Zhang <william.zhang@broadcom.com>
> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
> 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: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/mtd/nand/raw/brcmnand/brcmnand.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index 700d1122639f..46a4107a83a9 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -1011,6 +1011,14 @@ static int bcmnand_ctrl_poll_status(struct
> brcmnand_controller *ctrl,
>  	} while (get_timer(base) < limit);
>  #endif /* __UBOOT__ */
>
> +	/*
> +	 * 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);
>
>
> --
> 2.46.0

Reviewed-by: William Zhang <william.zhang@broadcom.com>

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