On Mon, Dec 19, 2011 at 10:01 PM, Felipe Contreras <felipe.contreras@xxxxxxxxx> wrote: > From: Felipe Contreras <felipe.contreras@xxxxxxxxx> > > In musb_init_controller() there's a pm_runtime_put(), but there's no > pm_runtime_get(), which creates a mismatch that causes the driver to > sleep when it shouldn't. This patch is causing problems here, the device never suspends, I've verified musb_runtime_suspend and omap2430_runtime_suspend are never called in my setup, unless I revert this patch. I'm using musb with ethernet gadget; cable removal also doesn't suspend musb. It seems pm_runtime_put() that was removed was balancing out pm_runtime_get in musb_platform_init(), which is called at the beginning of musb_init_controller(). I think this pm_runtime_get() from musb_platform_init() should be moved to musb_init_controller() to stop confusing people and pm_runtime_put() needs to be brought back. I can do a patch if nobody objects. > This was introduced in 7acc619[1], but it wasn't triggered in my setup > until 18a2689[2] was merged to Linus' branch at point df0914[3]. IOW; > when PM is working as it was supposed to. > > However, it seems most of the time this is used in a way that keeps the > counter above 0, so nobody noticed. Also, it seems to depend on the > configuration used in versions before 3.1, but not later (or in it). > > I found the problem by loading isp1704_charger before any usb gadgets: > http://article.gmane.org/gmane.linux.kernel/1226122 isp1704_charger seems to be doing otg_io_read(), and it's perfectly normal that musb can be suspended at the time isp1704 decides to do this. I think proper fix is to wake up must on musb_ulpi_read() and musb_ulpi_write() instead. > > All versions after 2.6.39 are affected. > > [1] usb: musb: Idle path retention and offmode support for OMAP3 > [2] OMAP2+: musb: hwmod adaptation for musb registration > [3] Merge branch 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 > > Cc: stable@xxxxxxxxxxxxxxx > Cc: Hema HK <hemahk@xxxxxx> > Signed-off-by: Felipe Contreras <felipe.contreras@xxxxxxxxx> > --- > drivers/usb/musb/musb_core.c | 2 -- > 1 files changed, 0 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > index b63ab15..920f04e 100644 > --- a/drivers/usb/musb/musb_core.c > +++ b/drivers/usb/musb/musb_core.c > @@ -2012,8 +2012,6 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl) > if (status < 0) > goto fail3; > > - pm_runtime_put(musb->controller); > - > status = musb_init_debugfs(musb); > if (status < 0) > goto fail4; > -- > 1.7.8 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gražvydas -- 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
