> Am 03.08.2016 um 17:38 schrieb Andreas Kemnade <andreas@xxxxxxxxxxxx>: > > The code assumes that omap2430_musb_enable() and > omap2430_musb_disable() are called in a balanced way. > That fact is broken by the fact that musb_init_controller() calls > musb_platform_disable() to switch from unknown state to off state > on initialisation. > > That means that phy_power_off() is called first so that > phy->power_count gets -1 and the phy is not enabled on phy_power_on(). > So when usb gadget is started the phy is not powered on. > Depending on the phy used that caused various problems. > Besides of causing usb problems, that can also have side effects. > > In the case of using the phy_twl4030, that prevents also charging > the battery via usb (using twl4030_charger) and so makes further > kernel debugging hard. > The problem was seen with 4.7 on an openphoenux gta04. It has a DM3730 > SoC and a TPS65950 companion. phy->power never became 1 s/TPS65950/TPS65950 (twl4030)/ > and so the usb did get powered on. s/did get/did not get/ maybe add: All this prevents detection of cable plugin-events and VBUS measurement and setting OTG_EN before charging is attempted. > > The patch prevents phy_power_off() from being called when > it is already off. > > Signed-off-by: Andreas Kemnade <andreas@xxxxxxxxxxxx> > --- > changes in v2: > improved commit message > > drivers/usb/musb/omap2430.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c > index 0b4cec9..c1a2b7b 100644 > --- a/drivers/usb/musb/omap2430.c > +++ b/drivers/usb/musb/omap2430.c > @@ -413,9 +413,10 @@ static void omap2430_musb_disable(struct musb *musb) > struct device *dev = musb->controller; > struct omap2430_glue *glue = dev_get_drvdata(dev->parent); > > - if (!WARN_ON(!musb->phy)) > - phy_power_off(musb->phy); > - > + if (glue->enabled) { > + if (!WARN_ON(!musb->phy)) > + phy_power_off(musb->phy); > + } > if (glue->status != MUSB_UNKNOWN) > omap_control_usb_set_mode(glue->control_otghs, > USB_MODE_DISCONNECT); > -- > 2.1.4 > > _______________________________________________ > http://projects.goldelico.com/p/gta04-kernel/ > Letux-kernel mailing list > Letux-kernel@xxxxxxxxxxxxxxx > http://lists.goldelico.com/mailman/listinfo.cgi/letux-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html