Re: [PATCH] spi: cadence-quadspi: Fix clock enable underflows due to runtime PM

["Dutta, Anurag" <a-dutta@ti.com>]

Hi Mark and Nishanth The below seems to work for me on j721e. Let me 
know your thoughts. Apply over 6987d58a9cbc5bd57c983baa514474a86c945d56. 
Also, the error actually comes from : if (cqspi->use_direct_mode) { ret 
= cqspi_request_mmap_dma(cqspi); if (ret == -EPROBE_DEFER) goto 
probe_setup_failed; } And not from flash_setup().

diff --git a/drivers/spi/spi-cadence-quadspi.c 
b/drivers/spi/spi-cadence-quadspi.c index af6d050da1c8..492b44976e52 
100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ 
b/drivers/spi/spi-cadence-quadspi.c @@ -2024,7 +2024,7 @@ static int 
cqspi_probe(struct platform_device *pdev) probe_reset_failed: if 
(cqspi->is_jh7110) cqspi_jh7110_disable_clk(pdev, cqspi); - 
clk_disable_unprepare(cqspi->clk); + pm_runtime_force_suspend(dev); 
probe_clk_failed: return ret; }

Regards Anurag

On 04-12-2025 22:35, Mark Brown wrote:
> On Thu, Dec 04, 2025 at 03:11:26PM +0000, Mark Brown wrote:
>> On Thu, Dec 04, 2025 at 08:05:30AM -0600, Nishanth Menon wrote:
>>> The clock is already turned off by the runtime-PM suspend callback, so an
>>> extra clk_disable*_unprepare() is only correct when runtime-PM support is
>>> not in use.
>> Right, I'm pretty sure that's where the extra disable is coming from.
>> The pm_runtime_set_active() further up the function is looking rather
>> suspect here.
> qspi_setup_flash() is just reading DT data, it's not actually
> interacting with the hardware at all, so I think we can sidestep the
> immediate issue by just moving it to where we parse the DT for the
> controller.  It's not fixing the actual issue with the missing/extra
> clock reference but it does get us back to where we were:
>
> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
> index af6d050da1c8..bdbeef05cd72 100644
> --- a/drivers/spi/spi-cadence-quadspi.c
> +++ b/drivers/spi/spi-cadence-quadspi.c
> @@ -1845,6 +1845,12 @@ static int cqspi_probe(struct platform_device *pdev)
>   		return -ENODEV;
>   	}
>   
> +	ret = cqspi_setup_flash(cqspi);
> +	if (ret) {
> +		dev_err(dev, "failed to setup flash parameters %d\n", ret);
> +		return ret;
> +	}
> +
>   	/* Obtain QSPI clock. */
>   	cqspi->clk = devm_clk_get(dev, NULL);
>   	if (IS_ERR(cqspi->clk)) {
> @@ -1988,12 +1994,6 @@ static int cqspi_probe(struct platform_device *pdev)
>   		pm_runtime_get_noresume(dev);
>   	}
>   
> -	ret = cqspi_setup_flash(cqspi);
> -	if (ret) {
> -		dev_err(dev, "failed to setup flash parameters %d\n", ret);
> -		goto probe_setup_failed;
> -	}
> -
>   	host->num_chipselect = cqspi->num_chipselect;
>   
>   	if (ddata && (ddata->quirks & CQSPI_SUPPORT_DEVICE_RESET))
>
> I'll send this out later assuming nothing blows up in my CI and nobody
> else notices an issue.