Hi,
On 23/02/15 17:26, Roger Quadros wrote:
> If a NAND device is not really present or pin muxes are not correctly
> configured we can lock up the kernel waiting infinitely for NAND_STATUS
> to be ready.
>
> This can be easily reproduced on TI's DRA7-evm board by booting it
> without NAND support in u-boot and disabling NAND pin muxes in the kernel.
>
> Add timeout when waiting for NAND_CMD_RESET completion. As per ONFi v4.0
> tRST can be upto 250ms for EZ-NAND and 5ms for raw NAND.
Any comments on this patch?
cheers,
-roger
>
> Signed-off-by: Roger Quadros <rog...@ti.com>
> Tested-by: Nishanth Menon <n...@ti.com>
> ---
> drivers/mtd/nand/nand_base.c | 27 +++++++++++++++++++++++----
> 1 file changed, 23 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index df7eb4f..d1e6695 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -566,6 +566,25 @@ void nand_wait_ready(struct mtd_info *mtd)
> EXPORT_SYMBOL_GPL(nand_wait_ready);
>
> /**
> + * nand_wait_status_ready - [GENERIC] Wait for the ready status after
> commands.
> + * @mtd: MTD device structure
> + * @timeo: Timeout in ms
> + *
> + * Wait for status ready (i.e. command done) or timeout.
> + */
> +static void nand_wait_status_ready(struct mtd_info *mtd, unsigned long timeo)
> +{
> + register struct nand_chip *chip = mtd->priv;
> +
> + timeo = jiffies + msecs_to_jiffies(timeo);
> + do {
> + if ((chip->read_byte(mtd) & NAND_STATUS_READY))
> + break;
> + touch_softlockup_watchdog();
> + } while (time_before(jiffies, timeo));
> +};
> +
> +/**
> * nand_command - [DEFAULT] Send command to NAND device
> * @mtd: MTD device structure
> * @command: the command to be sent
> @@ -643,8 +662,8 @@ static void nand_command(struct mtd_info *mtd, unsigned
> int command,
> NAND_CTRL_CLE | NAND_CTRL_CHANGE);
> chip->cmd_ctrl(mtd,
> NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
> - while (!(chip->read_byte(mtd) & NAND_STATUS_READY))
> - ;
> + /* EZ-NAND can take upto 250ms as per ONFi v4.0 */
> + nand_wait_status_ready(mtd, 250);
> return;
>
> /* This applies to read commands */
> @@ -740,8 +759,8 @@ static void nand_command_lp(struct mtd_info *mtd,
> unsigned int command,
> NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
> chip->cmd_ctrl(mtd, NAND_CMD_NONE,
> NAND_NCE | NAND_CTRL_CHANGE);
> - while (!(chip->read_byte(mtd) & NAND_STATUS_READY))
> - ;
> + /* EZ-NAND can take upto 250ms as per ONFi v4.0 */
> + nand_wait_status_ready(mtd, 250);
> return;
>
> case NAND_CMD_RNDOUT:
>
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