[PATCH] drivers: spi: Fix data loss issue in QSPI

[Chee, Tien Fong]

> -----Original Message-----
> From: Ravulapalli, Naresh Kumar <naresh.kumar.ravulapalli at altera.com>
> Sent: Friday, March 7, 2025 5:38 PM
> To: u-boot at lists.denx.de
> Cc: Marek Vasut <marex at denx.de>; Simon Goldschmidt
> <simon.k.r.goldschmidt at gmail.com>; Chee, Tien Fong
> <tien.fong.chee at altera.com>; Jagan Teki <jagan at amarulasolutions.com>;
> Tom Rini <trini at konsulko.com>; Ravulapalli, Naresh Kumar
> <naresh.kumar.ravulapalli at altera.com>
> Subject: [PATCH] drivers: spi: Fix data loss issue in QSPI
> 
> QSPI driver performs chip select operation before every read/write access.
> During this operation, driver needs to enable and disable the QSPI controller.
> This may cause data loss if there is inadvertent halting of any ongoing
> read/write operation. To avoid this scenario, waiting for the QSPI status to be
> idle before next read/write operation is implemented.
> 
> Signed-off-by: Naresh Kumar Ravulapalli
> <nareshkumar.ravulapalli at altera.com>
> ---
>  drivers/spi/cadence_qspi_apb.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/spi/cadence_qspi_apb.c
> b/drivers/spi/cadence_qspi_apb.c index f2f69cf9f1..b579699d2e 100644
> --- a/drivers/spi/cadence_qspi_apb.c
> +++ b/drivers/spi/cadence_qspi_apb.c
> @@ -747,6 +747,10 @@ cadence_qspi_apb_indirect_read_execute(struct
> cadence_spi_priv *priv,
>  		goto failrd;
>  	}
> 
> +	/* Wait til QSPI is idle */
> +	if (!cadence_qspi_wait_idle(priv->regbase))
> +		return -EIO;
> +
>  	return 0;
> 
>  failrd:
> @@ -914,6 +918,11 @@ cadence_qspi_apb_indirect_write_execute(struct
> cadence_spi_priv *priv,
> 
>  	if (bounce_buf)
>  		free(bounce_buf);
> +
> +	/* Wait til QSPI is idle */
> +	if (!cadence_qspi_wait_idle(priv->regbase))
> +		return -EIO;
> +
>  	return 0;
> 
>  failwr:
> --
> 2.35.3

Reviewed-by: Tien Fong Chee <tien.fong.chee at intel.com>

Best regards,
Tien Fong