Messages in this thread | | | From | Linus Walleij <> | Date | Wed, 18 Nov 2020 01:38:50 +0100 | Subject | Re: [LINUX PATCH V3 7/9] gpio: gpio-xilinx: Add support for suspend and resume |
| |
Hi Srinivas,
On Thu, Nov 12, 2020 at 6:13 PM Srinivas Neeli <srinivas.neeli@xilinx.com> wrote:
> Add support for suspend and resume, pm runtime suspend and resume. > Added free and request calls. > > Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com> > --- > Changes in V3: > -Created new patch for suspend and resume.
(...)
I'm following the idea here I think.
> @@ -544,6 +618,8 @@ static int xgpio_probe(struct platform_device *pdev)
> + pm_runtime_enable(&pdev->dev); > + status = pm_runtime_get_sync(&pdev->dev); > + if (status < 0) > + goto err_unprepare_clk;
Now the clock is enabled a second time. Because runtime PM kicks in.
Do this instead: pm_runtime_get_noresume() pm_runtime_set_active() pm_runtime_enable()
Now runtime PM knows it is active and will not call runtime resume and enable the clock a second time.
> + pm_runtime_put(&pdev->dev); > return 0;
This is right, now pm runtime will gate the clock until the first GPIO is requested.
> +err_pm_put: > + pm_runtime_put_sync(&pdev->dev); > err_unprepare_clk: > + pm_runtime_disable(&pdev->dev); > clk_disable_unprepare(chip->clk); > return status;
Use this on the errorpath instead: pm_runtime_put_noidle() pm_runtime_disable() clk_disable_unprepare();
Now the code will not call runtime suspend to gate the clock a second time.
Double-check the references to the clock and check in debugfs that the clock really gets disabled if you're not using any GPIOs.
Yours, Linus Walleij
| |