Re: [PATCH 016/347] FogBugz #516535: Fix QSPI write issues

[Vignesh Raghavendra <vigneshr@ti.com>]

Hi,

On 30/08/22 11:50 am, Jit Loon Lim wrote:
> From: Chee Hong Ang <chee.hong.ang@intel.com>
> 
> QSPI driver perform chip select on every flash read/write
> access. The driver need to disable/enable the QSPI controller
> while performing chip select. This may cause some data lost
> especially the QSPI controller is configured to run at slower
> speed as it may take longer time to access the flash device.
> This patch prevent the driver from disable/enable the QSPI
> controller too soon and inadvertently halting any ongoing flash
> read/write access by ensuring the QSPI controller is always in
> idle mode after each read/write access.
> 
> Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>
> ---
>  drivers/spi/cadence_qspi_apb.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
> index 2cdf4c9c9f..5e03495f45 100644
> --- a/drivers/spi/cadence_qspi_apb.c
> +++ b/drivers/spi/cadence_qspi_apb.c
> @@ -858,13 +858,9 @@ cadence_qspi_apb_indirect_read_execute(struct cadence_spi_plat *plat,
>  	writel(CQSPI_REG_INDIRECTRD_DONE,
>  	       plat->regbase + CQSPI_REG_INDIRECTRD);
>  
> -	/* Check indirect done status */
> -	ret = wait_for_bit_le32(plat->regbase + CQSPI_REG_INDIRECTRD,
> -				CQSPI_REG_INDIRECTRD_DONE, 0, 10, 0);
> -	if (ret) {
> -		printf("Indirect read clear completion error (%i)\n", ret);
> -		goto failrd;
> -	}

Why would you drop looking at CQSPI_REG_INDIRECTRD_DONE status bit? This
gives out a much granular error wrt what operation actually failed.


> +	/* Wait til QSPI is idle */
> +	if (!cadence_qspi_wait_idle(plat->regbase))
> +		return -EIO;
>  
>  	return 0;
>  
> @@ -1031,6 +1027,11 @@ cadence_qspi_apb_indirect_write_execute(struct cadence_spi_plat *plat,
>  
>  	if (bounce_buf)
>  		free(bounce_buf);
> +
> +	/* Wait til QSPI is idle */
> +	if (!cadence_qspi_wait_idle(plat->regbase))
> +		return -EIO;
> +
>  	return 0;
>  
>  failwr: