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

Vignesh Raghavendra
2022-10-25T06:08:41Z

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;
>