Re: [PATCH v5 07/17] spi: cadence-quadspi: add DQS support to read data capture

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The patch adds a `dqs` parameter to `cqspi_readdata_capture()` but hardcodes it to `false` in its only caller, which unconditionally clears the DQS hardware bit and destroys any preexisting bootloader configuration.
--

--- Patch [7]: [PATCH v5 07/17] spi: cadence-quadspi: add DQS support to read data capture ---
commit 9c04e0d8a632e24ea7f330776f17875445decaac
Author: Santhosh Kumar K <s-k6@ti.com>

spi: cadence-quadspi: add DQS support to read data capture

This commit adds a DQS (Data Strobe) parameter to cqspi_readdata_capture()
to control data capture timing. It updates the register read-modify-write
sequence to configure the DQS bit and modifies the caller to provide this
new parameter.

> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
> index f8e2663723677..046fa5d69b0f7 100644
> --- a/drivers/spi/spi-cadence-quadspi.c
> +++ b/drivers/spi/spi-cadence-quadspi.c
[ ... ]
> @@ -476,6 +477,11 @@ static void cqspi_readdata_capture(struct cqspi_st *cqspi, const bool bypass,
>  	reg |= (delay & CQSPI_REG_READCAPTURE_DELAY_MASK)
>  	       << CQSPI_REG_READCAPTURE_DELAY_LSB;
>  
> +	if (dqs)
> +		reg |= BIT(CQSPI_REG_READCAPTURE_DQS_LSB);
> +	else
> +		reg &= ~BIT(CQSPI_REG_READCAPTURE_DQS_LSB);
> +
>  	writel(reg, reg_base + CQSPI_REG_READCAPTURE);
>  }
>  
> @@ -1317,7 +1323,7 @@ static void cqspi_configure(struct cqspi_flash_pdata *f_pdata,
>  		cqspi->sclk = sclk;
>  		cqspi_config_baudrate_div(cqspi);
>  		cqspi_delay(f_pdata);
> -		cqspi_readdata_capture(cqspi, !cqspi->rclk_en,
> +		cqspi_readdata_capture(cqspi, !cqspi->rclk_en, false,

[Severity: Medium]
Does passing false here unconditionally clear the DQS hardware bit that was
previously preserved from the bootloader?

Prior to this change, the read-modify-write sequence in
cqspi_readdata_capture() did not touch bit 8 (CQSPI_REG_READCAPTURE_DQS_LSB).
Now, by hardcoding dqs to false, cqspi_readdata_capture() will actively clear
the DQS bit.

Could this degrade timing margins and cause read data corruption on platforms
that currently rely on the bootloader's DQS configuration?

>  				       f_pdata->read_delay);
>  	}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260717185116.2065505-1-s-k6@ti.com?part=7