On 24-12-10 18:13:36, Théo Lebrun wrote: > At runtime_resume(), read the W1 (Wrapper Register 1) register to detect > if an hardware reset occurred. If it did, run the hardware init sequence. > > This callback will be called at system-wide resume. Previously, if a > reset occurred during suspend, we would crash. The wrapper config had > not been written, leading to invalid register accesses inside cdns3. > > Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx> > --- > drivers/usb/cdns3/cdns3-ti.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c > index d704eb39820ad08a8774be7f00aa473c3ff267c0..d35be7db7616ef5e5bed7dbd53b78a094809f7cc 100644 > --- a/drivers/usb/cdns3/cdns3-ti.c > +++ b/drivers/usb/cdns3/cdns3-ti.c > @@ -188,6 +188,12 @@ static int cdns_ti_probe(struct platform_device *pdev) > data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider"); > data->usb2_only = device_property_read_bool(dev, "ti,usb2-only"); > > + /* > + * The call below to pm_runtime_get_sync() MIGHT reset hardware, if it > + * detects it as uninitialised. We want to enforce a reset at probe, > + * and so do it manually here. This means the first runtime_resume() > + * will be a no-op. > + */ > cdns_ti_reset_and_init_hw(data); > > pm_runtime_enable(dev); > @@ -232,6 +238,24 @@ static void cdns_ti_remove(struct platform_device *pdev) > platform_set_drvdata(pdev, NULL); > } > > +static int cdns_ti_runtime_resume(struct device *dev) > +{ > + const u32 mask = USBSS_W1_PWRUP_RST | USBSS_W1_MODESTRAP_SEL; > + struct cdns_ti *data = dev_get_drvdata(dev); > + u32 w1; > + > + w1 = cdns_ti_readl(data, USBSS_W1); > + if ((w1 & mask) != mask) > + cdns_ti_reset_and_init_hw(data); > + > + return 0; > +} > + > +static const struct dev_pm_ops cdns_ti_pm_ops = { > + RUNTIME_PM_OPS(NULL, cdns_ti_runtime_resume, NULL) Why only runtime resume, but without runtime suspend? Peter