On Thu, Feb 26, 2015 at 02:25:20PM -0600, Bin Liu wrote:
> On Thu, Feb 26, 2015 at 2:19 PM, Felipe Balbi <balbi@xxxxxx> wrote:
> > Hi again,
> >
> > On Thu, Feb 26, 2015 at 02:15:40PM -0600, Felipe Balbi wrote:
> >> > > >> >> > On Thu, Feb 26, 2015 at 12:25:16PM -0600, Felipe Balbi wrote:
> >> > > >> >> >> FSDEV is set for both HIGH and FULL speeds,
> >> > > >> >> >> the correct HIGHSPEED check is done through
> >> > > >> >> >> power register's HSMODE bit.
> >> > > >> >> >>
> >> > > >> >> >> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> >> > > >> >> >
> >> > > >> >> > I'm still unsure if we should really ignore babble on FS/LS. It seems to
> >> > > >> >> > me we should never ignore it, but I really don't have a way to prove
> >> > > >> >> > this statement. For the sake of reducing impact, we will just fix HS
> >> > > >> >> > check here.
> >> > > >> >> >
> >> > > >> >>
> >> > > >> >> I believe we should drop speed check in here and not ignore babble
> >> > > >> >> regardless. We have seen many cases that full-speed babble causes MUSB
> >> > > >> >> stop working.
> >> > > >> >
> >> > > >> > I'll make that as a separate patch then, just to make sure we can revert
> >> > > >> > it later if something goes wrong ;-)
> >> > > >>
> >> > > >> Agreed.
> >> > > >
> >> > > > I noticed something else. If we really don't need to reset musb in case
> >> > > > of babble, then we can drop that recover_work completely which
> >> > > > simplifies babble handling quite a bit.
> >> > > >
> >> > > > I'll fiddle with that, if you don't mind.
> >> > >
> >> > > That is fine with me. I am writing the comments for the dropping reset
> >> > > patch right now ;)
> >> > >
> >> > > We only need the following in musb_recover_work() for the recovery.
> >> > >
> >> > > 1852 /*
> >> > > 1853 * When a babble condition occurs, the musb controller
> >> > > 1854 * removes the session bit and the endpoint config is lost.
> >> > > 1855 */
> >> > > 1856 if (musb->dyn_fifo)
> >> > > 1857 status = ep_config_from_table(musb);
> >> > > 1858 else
> >> > > 1859 status = ep_config_from_hw(musb);
> >> > > 1860
> >> > > 1861 /* start the session again */
> >> > > 1862 if (status == 0)
> >> > > 1863 musb_start(musb);
> >> >
> >> > the statement that musb looses ep configuration seems bogus to me. I
> >> > dropped that too:
> >> >
> >> > commit 4a07d415bf5894c66f61827c30053a65d6dfce26
> >> > Author: Felipe Balbi <balbi@xxxxxx>
> >> > Date: Thu Feb 26 14:02:35 2015 -0600
> >> >
> >> > usb: musb: core: simplify musb_recover_work()
> >> >
> >> > we're not resetting musb at all, just restarting
> >> > the session. This means we don't need to touch PHYs
> >> > or VBUS or anything like that. Just make sure session
> >> > bit is reenabled after MUSB dropped it.
> >> >
> >> > Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> >> >
> >> > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> >> > index d9c627d54db6..219636c1b020 100644
> >> > --- a/drivers/usb/musb/musb_core.c
> >> > +++ b/drivers/usb/musb/musb_core.c
> >> > @@ -1835,7 +1835,8 @@ static void musb_irq_work(struct work_struct *data)
> >> > static void musb_recover_work(struct work_struct *data)
> >> > {
> >> > struct musb *musb = container_of(data, struct musb, recover_work.work);
> >> > - int status, ret;
> >> > + int ret;
> >> > + u8 devctl;
> >> >
> >> > ret = musb_platform_reset(musb);
> >> > if (ret) {
> >> > @@ -1843,24 +1844,17 @@ static void musb_recover_work(struct work_struct *data)
> >> > return;
> >> > }
> >> >
> >> > - usb_phy_vbus_off(musb->xceiv);
> >> > - usleep_range(100, 200);
> >> > -
> >> > - usb_phy_vbus_on(musb->xceiv);
> >> > - usleep_range(100, 200);
> >> > + /* drop session bit */
> >> > + devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
> >> > + devctl &= ~MUSB_DEVCTL_SESSION;
> >> > + musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
> >> >
> >> > - /*
> >> > - * When a babble condition occurs, the musb controller
> >> > - * removes the session bit and the endpoint config is lost.
> >> > - */
> >> > - if (musb->dyn_fifo)
> >> > - status = ep_config_from_table(musb);
> >> > - else
> >> > - status = ep_config_from_hw(musb);
> >> > + /* wait for session to really drop */
> >> > + udelay(100);
> >> >
> >> > - /* start the session again */
> >> > - if (status == 0)
> >> > - musb_start(musb);
> >> > + /* restart session */
> >> > + devctl |= MUSB_DEVCTL_SESSION;
> >> > + musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
> >> > }
> >> >
> >> > /* --------------------------------------------------------------------------
> >> >
> >> >
> >> > the only thing that we're still missing is a notification to usbcore
> >> > that we have a port being disabled, that's the only way to have testusb
> >> > know that it has been disconnected by the host.
> >>
> >> here's the final version:
> >>
> >> commit 3db11e7da5938bbd955410355194625f699a424c
> >> Author: Felipe Balbi <balbi@xxxxxx>
> >> Date: Thu Feb 26 14:02:35 2015 -0600
> >>
> >> usb: musb: core: simplify musb_recover_work()
> >>
> >> we're not resetting musb at all, just restarting
> >> the session. This means we don't need to touch PHYs
> >> or VBUS or anything like that. Just make sure session
> >> bit is reenabled after MUSB dropped it.
> >>
> >> while at that, make sure to tell usbcore that we're
> >> dropping the session and, thus, disconnecting the
> >> device.
> >>
> >> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> >>
> >> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> >> index d9c627d54db6..64cb242d92f7 100644
> >> --- a/drivers/usb/musb/musb_core.c
> >> +++ b/drivers/usb/musb/musb_core.c
> >> @@ -1835,7 +1835,8 @@ static void musb_irq_work(struct work_struct *data)
> >> static void musb_recover_work(struct work_struct *data)
> >> {
> >> struct musb *musb = container_of(data, struct musb, recover_work.work);
> >> - int status, ret;
> >> + int ret;
> >> + u8 devctl;
> >>
> >> ret = musb_platform_reset(musb);
> >> if (ret) {
> >> @@ -1843,24 +1844,17 @@ static void musb_recover_work(struct work_struct *data)
> >> return;
> >> }
> >>
> >> - usb_phy_vbus_off(musb->xceiv);
> >> - usleep_range(100, 200);
> >> -
> >> - usb_phy_vbus_on(musb->xceiv);
> >> - usleep_range(100, 200);
> >> + /* drop session bit */
> >> + devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
> >> + devctl &= ~MUSB_DEVCTL_SESSION;
> >> + musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
> >>
> >> - /*
> >> - * When a babble condition occurs, the musb controller
> >> - * removes the session bit and the endpoint config is lost.
> >> - */
> >> - if (musb->dyn_fifo)
> >> - status = ep_config_from_table(musb);
> >> - else
> >> - status = ep_config_from_hw(musb);
> >> + /* tell usbcore about it */
> >> + musb_root_disconnect(musb);
> >>
> >> - /* start the session again */
> >> - if (status == 0)
> >> - musb_start(musb);
> >> + /* restart session */
> >> + devctl |= MUSB_DEVCTL_SESSION;
> >> + musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
> >> }
> >>
> >> /* --------------------------------------------------------------------------
> >>
> >> now I'll move all of this inside the irq handler and rename
> >> musb_platform_reset() to musb_platform_recover_from_babble()
> >
> > it looks like we really do need to redo fifo sizing. So here's a version
> > which I tested and can see that even after babble, device reenumerates.
> >
> > commit 1b9f864804aab6b250084b7adab9b520903f0a1d
> > Author: Felipe Balbi <balbi@xxxxxx>
> > Date: Thu Feb 26 14:02:35 2015 -0600
> >
> > usb: musb: core: simplify musb_recover_work()
> >
> > we're not resetting musb at all, just restarting
> > the session. This means we don't need to touch PHYs
> > or VBUS or anything like that. Just make sure session
> > bit is reenabled after MUSB dropped it.
> >
> > while at that, make sure to tell usbcore that we're
> > dropping the session and, thus, disconnecting the
> > device.
> >
> > Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> >
> > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> > index d9c627d54db6..1ae4c3c28d68 100644
> > --- a/drivers/usb/musb/musb_core.c
> > +++ b/drivers/usb/musb/musb_core.c
> > @@ -1835,7 +1835,8 @@ static void musb_irq_work(struct work_struct *data)
> > static void musb_recover_work(struct work_struct *data)
> > {
> > struct musb *musb = container_of(data, struct musb, recover_work.work);
> > - int status, ret;
> > + int ret;
> > + u8 devctl;
> >
> > ret = musb_platform_reset(musb);
> > if (ret) {
> > @@ -1843,23 +1844,25 @@ static void musb_recover_work(struct work_struct *data)
> > return;
> > }
> >
> > - usb_phy_vbus_off(musb->xceiv);
> > - usleep_range(100, 200);
> > + /* drop session bit */
> > + devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
> > + devctl &= ~MUSB_DEVCTL_SESSION;
> > + musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
> >
> > - usb_phy_vbus_on(musb->xceiv);
> > - usleep_range(100, 200);
> > + /* tell usbcore about it */
> > + musb_root_disconnect(musb);
> >
> > /*
> > * When a babble condition occurs, the musb controller
> > * removes the session bit and the endpoint config is lost.
> > */
> > if (musb->dyn_fifo)
> > - status = ep_config_from_table(musb);
> > + ret = ep_config_from_table(musb);
> > else
> > - status = ep_config_from_hw(musb);
> > + ret = ep_config_from_hw(musb);
> >
> > - /* start the session again */
> > - if (status == 0)
> > + /* restart session */
> > + if (ret == 0)
> > musb_start(musb);
> > }
> >
>
> Looks good to me. You also need the following to not reset MUSB.
>
> diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
> index b52eeca..4da8388 100644
> --- a/drivers/usb/musb/musb_dsps.c
> +++ b/drivers/usb/musb/musb_dsps.c
> @@ -592,20 +592,8 @@ static int dsps_musb_reset(struct musb *musb)
>
> if (glue->sw_babble_enabled)
> session_restart = dsps_sw_babble_control(musb);
> - /*
> - * In case of new silicon version babble condition can be recovered
> - * without resetting the MUSB. But for older silicon versions, MUSB
> - * reset is needed
> - */
> - if (session_restart || !glue->sw_babble_enabled) {
> - dev_info(musb->controller, "Restarting MUSB to recover
> from Babble\n");
> - dsps_writel(musb->ctrl_base, wrp->control, (1 << wrp->reset));
> - usleep_range(100, 200);
> - usb_phy_shutdown(musb->xceiv);
> - usleep_range(100, 200);
> - usb_phy_init(musb->xceiv);
> + else
> session_restart = 1;
> - }
>
> return session_restart ? 0 : -EPIPE;
> }
got that covered too :-)
https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testing/next&id=12326d485aa676a09bc17026dce9094394db8bdc
--
balbi
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