diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2012-10-30 22:52:23 +0400 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2012-10-31 17:20:40 +0400 |
| commit | b11e94d03726c5dbee0d9a841a025313504e90f4 (patch) | |
| tree | 1c0b0f9dd296ca4580ad87b5d041b4a832f83d5c | |
| parent | 4b0de6f38362960460d3693f122c6abe6bb0704b (diff) | |
| download | linux-b11e94d03726c5dbee0d9a841a025313504e90f4.tar.xz | |
usb: musb: read MUSB_POWER register only when required.
This is part of the workaround for AM35x advisory Advisory 1.1.20.
The advisory says that the IPSS bridge can't handle 8 & 16 bit read
access. An 8bit read access to MUSB_POWER results in an 32bit read
access which also reads INTRTX and therefore may lose interrupts.
This patch tries to minimize reads to MUSB_POWER and perform them only
when required.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
| -rw-r--r-- | drivers/usb/musb/musb_core.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index bb56a0e8b23b..d156fe8bebfa 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -467,12 +467,12 @@ void musb_hnp_stop(struct musb *musb) */ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb, - u8 devctl, u8 power) + u8 devctl) { struct usb_otg *otg = musb->xceiv->otg; irqreturn_t handled = IRQ_NONE; - dev_dbg(musb->controller, "<== Power=%02x, DevCtl=%02x, int_usb=0x%x\n", power, devctl, + dev_dbg(musb->controller, "<== DevCtl=%02x, int_usb=0x%x\n", devctl, int_usb); /* in host mode, the peripheral may issue remote wakeup. @@ -485,6 +485,7 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb, if (devctl & MUSB_DEVCTL_HM) { void __iomem *mbase = musb->mregs; + u8 power; switch (musb->xceiv->state) { case OTG_STATE_A_SUSPEND: @@ -492,6 +493,7 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb, * will stop RESUME signaling */ + power = musb_readb(musb->mregs, MUSB_POWER); if (power & MUSB_POWER_SUSPENDM) { /* spurious */ musb->int_usb &= ~MUSB_INTR_SUSPEND; @@ -655,8 +657,8 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb, } if (int_usb & MUSB_INTR_SUSPEND) { - dev_dbg(musb->controller, "SUSPEND (%s) devctl %02x power %02x\n", - otg_state_string(musb->xceiv->state), devctl, power); + dev_dbg(musb->controller, "SUSPEND (%s) devctl %02x\n", + otg_state_string(musb->xceiv->state), devctl); handled = IRQ_HANDLED; switch (musb->xceiv->state) { @@ -1560,12 +1562,11 @@ static irqreturn_t generic_interrupt(int irq, void *__hci) irqreturn_t musb_interrupt(struct musb *musb) { irqreturn_t retval = IRQ_NONE; - u8 devctl, power; + u8 devctl; int ep_num; u32 reg; devctl = musb_readb(musb->mregs, MUSB_DEVCTL); - power = musb_readb(musb->mregs, MUSB_POWER); dev_dbg(musb->controller, "** IRQ %s usb%04x tx%04x rx%04x\n", (devctl & MUSB_DEVCTL_HM) ? "host" : "peripheral", @@ -1576,7 +1577,7 @@ irqreturn_t musb_interrupt(struct musb *musb) */ if (musb->int_usb) retval |= musb_stage0_irq(musb, musb->int_usb, - devctl, power); + devctl); /* "stage 1" is handling endpoint irqs */ |