On omap platforms, when configuring the kernel, if we choose the musb
work as host or OTG mode and we plug
a mini-A cable into the socket, after the kernel boot up in host mode or
insmod gadget driver in OTG mode,
the state of musb's xceiv is A_IDLE or B_IDLE correspondingly because id
change can't trigger ISR. Under this
condition, if we hotplug a usb device(without self-powered) at the other
side of the cable, the musb will suffer a vbus error,
This patch can handle this vbus error.
Wang Hui wrote:
When the MUSB is configured as host mode or OTG mode, the xceiv->state
will be set to OTG_STATE_A_IDLE or OTG_STATE_B_IDLE unconditionally
during init process. These init states can change to other
states When the MUSB module detects id pin change, devices connect or
disconnect.
But on some platforms(omap2, omap3), the id pin change
can't raise IRQ request to the MUSB module, so on these platforms,
the init xceiv->state will be A_IDLE or B_IDLE. Under this condition,
when we want the MUSB to act as a host and hotplug a usb device in
mini-B side of the cable, the MUSB will have a possibility to suffer
power underrun under A_IDLE or B_IDLE state, So here adding these
two states under which we can handle VBUSERROR IRQ.
Signed-off-by: Wang Hui <hui.w...@windriver.com>
---
drivers/usb/musb/musb_core.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index b4bbf8f..655413c 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -516,6 +516,8 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8
int_usb,
* another reset is due (at least for high speed,
* to redo the chirp etc), it might work OK...
*/
+ case OTG_STATE_A_IDLE:
+ case OTG_STATE_B_IDLE:
case OTG_STATE_A_WAIT_BCON:
case OTG_STATE_A_WAIT_VRISE:
if (musb->vbuserr_retry) {
--
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