Hi,

On Sat, May 14, 2016 at 11:07:51AM +0200, Hans de Goede wrote:
> Hi,
> 
> On 13-05-16 20:35, Bin Liu wrote:
> >Hi,
> >
> >On Thu, May 12, 2016 at 08:31:09PM +0200, Hans de Goede wrote:
> >>When the board is powering attached usb devices via the otg port
> >>sometimes / on some devices it takes slightly too long for the VBus
> >>detection code in phy-sun4i-usb.c to signal that VBus is high after
> >>enabling VBus and the musb hardware signals a MUSB_INTR_VBUSERROR
> >>interrupt.
> >>
> >>This commit sets the otg state to A_WAIT_VRISE upon enabling Vbus
> >>making musb_stage0_irq() ignore the first VBUSERR_RETRY_COUNT
> >>VBUSERROR interrupts, fixing connection issues in these cases.
> >>
> >>Signed-off-by: Hans de Goede <hdego...@redhat.com>
> >>---
> >> drivers/usb/musb/sunxi.c | 8 +++++---
> >> 1 file changed, 5 insertions(+), 3 deletions(-)
> >>
> >>diff --git a/drivers/usb/musb/sunxi.c b/drivers/usb/musb/sunxi.c
> >>index 2c33d9b..2ee48fb 100644
> >>--- a/drivers/usb/musb/sunxi.c
> >>+++ b/drivers/usb/musb/sunxi.c
> >>@@ -112,7 +112,7 @@ static void sunxi_musb_work(struct work_struct *work)
> >>            if (test_bit(SUNXI_MUSB_FL_HOSTMODE, &glue->flags)) {
> >>                    set_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
> >>                    musb->xceiv->otg->default_a = 1;
> >>-                   musb->xceiv->otg->state = OTG_STATE_A_IDLE;
> >>+                   musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
> >>                    MUSB_HST_MODE(musb);
> >>                    devctl |= MUSB_DEVCTL_SESSION;
> >>            } else {
> >>@@ -145,9 +145,10 @@ static void sunxi_musb_set_vbus(struct musb *musb, int 
> >>is_on)
> >> {
> >>    struct sunxi_glue *glue = dev_get_drvdata(musb->controller->parent);
> >>
> >>-   if (is_on)
> >>+   if (is_on) {
> >>            set_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
> >>-   else
> >>+           musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
> >
> >Why this has to be set in both sunxi_musb_work() and here? Only setting
> >it in the work is not efficient?
> 
> Different code paths, sunxi_musb_work sets it when the id pin changes
> (gets pulled low), this function gets called by musb_core in response
> to a session-request interrupt.

Ok, I see what I missed. An interrupt could happen right after
_set_vbus() but before _musb_work().

Regards,
-Bin.

> 
> Regards,
> 
> Hans
> 
> 
> >
> >Regards,
> >-Bin.
> >
> >>+   } else
> >>            clear_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
> >>
> >>    schedule_work(&glue->work);
> >>@@ -325,6 +326,7 @@ static int sunxi_set_mode(struct musb *musb, u8 mode)
> >>            set_bit(SUNXI_MUSB_FL_PHY_ON, &glue->flags);
> >>            /* Stop musb work from turning vbus off again */
> >>            set_bit(SUNXI_MUSB_FL_VBUS_ON, &glue->flags);
> >>+           musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
> >>    }
> >>
> >>    return 0;
> >>--
> >>2.7.4
> >>
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