Re: [PATCH] spi: pxa2xx: Handle return value of clk_prepare_enable

From: Andy Shevchenko
Date: Tue Jun 06 2017 - 06:54:50 EST


On Tue, Jun 6, 2017 at 12:44 PM, Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote:
> clk_prepare_enable() can fail here and we must check its return value.

> @@ -1676,7 +1676,11 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)

> - clk_prepare_enable(ssp->clk);
> + status = clk_prepare_enable(ssp->clk);

This one looks fine.

> @@ -1855,8 +1859,13 @@ static int pxa2xx_spi_resume(struct device *dev)

> /* Enable the SSP clock */
> - if (!pm_runtime_suspended(dev))
> - clk_prepare_enable(ssp->clk);
> + if (!pm_runtime_suspended(dev)) {
> + status = clk_prepare_enable(ssp->clk);
> + if (status) {
> + dev_err(dev, "Failed to prepare clock\n");
> + return status;
> + }

This...

> @@ -1886,8 +1895,7 @@ static int pxa2xx_spi_runtime_resume(struct device *dev)
> {
> struct driver_data *drv_data = dev_get_drvdata(dev);
>
> - clk_prepare_enable(drv_data->ssp->clk);
> - return 0;
> + return clk_prepare_enable(drv_data->ssp->clk);

...and especially this should be carefully checked since there are
differences in behaviour how system or driver will be resumed.

So, the question is how did you test it?

--
With Best Regards,
Andy Shevchenko