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 16bit read access to MUSB_INTRRXE results in an 32bit read
access which also reads INTRUSB and therefore may lose interrupts.
This patch uses a shadow register of MUSB_INTRRXE so we only perform
write access to it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/usb/musb/musb_core.c | 10 ++++++----
drivers/usb/musb/musb_gadget.c | 11 ++++-------
2 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index d05439c..ee04eae 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -671,7 +671,8 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
/* REVISIT HNP; just force disconnect */
}
musb_writew(musb->mregs, MUSB_INTRTXE, musb->epmask);
- musb_writew(musb->mregs, MUSB_INTRRXE, musb->epmask & 0xfffe);
+ musb->context.intrrxe = musb->epmask & 0xfffe;
+ musb_writew(musb->mregs, MUSB_INTRRXE, musb->context.intrrxe);
musb_writeb(musb->mregs, MUSB_INTRUSBE, 0xf7);
musb->port1_status &= ~(USB_PORT_STAT_LOW_SPEED
|USB_PORT_STAT_HIGH_SPEED
@@ -893,7 +894,8 @@ void musb_start(struct musb *musb)
/* Set INT enable registers, enable interrupts */
musb_writew(regs, MUSB_INTRTXE, musb->epmask);
- musb_writew(regs, MUSB_INTRRXE, musb->epmask & 0xfffe);
+ musb->context.intrrxe = musb->epmask & 0xfffe;
+ musb_writew(musb->mregs, MUSB_INTRRXE, musb->context.intrrxe);
musb_writeb(regs, MUSB_INTRUSBE, 0xf7);
musb_writeb(regs, MUSB_TESTMODE, 0);
@@ -941,7 +943,8 @@ static void musb_generic_disable(struct musb *musb)
/* disable interrupts */
musb_writeb(mbase, MUSB_INTRUSBE, 0);
musb_writew(mbase, MUSB_INTRTXE, 0);
- musb_writew(mbase, MUSB_INTRRXE, 0);
+ musb->context.intrrxe = 0;
+ musb_writew(musb->mregs, MUSB_INTRRXE, musb->context.intrrxe);
/* off */
musb_writeb(mbase, MUSB_DEVCTL, 0);
@@ -2140,7 +2143,6 @@ static void musb_save_context(struct musb *musb)
}
musb->context.power = musb_readb(musb_base, MUSB_POWER);
musb->context.intrtxe = musb_readw(musb_base, MUSB_INTRTXE);
- musb->context.intrrxe = musb_readw(musb_base, MUSB_INTRRXE);
musb->context.intrusbe = musb_readb(musb_base, MUSB_INTRUSBE);
musb->context.index = musb_readb(musb_base, MUSB_INDEX);
musb->context.devctl = musb_readb(musb_base, MUSB_DEVCTL);
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index a495a30..629c2ea 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1119,8 +1119,6 @@ static int musb_gadget_enable(struct usb_ep *ep,
musb_writew(regs, MUSB_TXCSR, csr);
} else {
- u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
-
if (hw_ep->is_shared_fifo)
musb_ep->is_in = 0;
if (musb_ep->is_in)
@@ -1131,8 +1129,8 @@ static int musb_gadget_enable(struct usb_ep *ep,
goto fail;
}
- int_rxe |= (1 << epnum);
- musb_writew(mbase, MUSB_INTRRXE, int_rxe);
+ musb->context.intrrxe |= (1 << epnum);
+ musb_writew(mbase, MUSB_INTRRXE, musb->context.intrrxe);
/* REVISIT if can_bulk_combine() use by updating "tmp"
* likewise high bandwidth periodic rx
@@ -1225,9 +1223,8 @@ static int musb_gadget_disable(struct usb_ep *ep)
musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
musb_writew(epio, MUSB_TXMAXP, 0);
} else {
- u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
- int_rxe &= ~(1 << epnum);
- musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
+ musb->context.intrrxe &= ~(1 << epnum);
+ musb_writew(musb->mregs, MUSB_INTRRXE, musb->context.intrrxe);
musb_writew(epio, MUSB_RXMAXP, 0);
}
--
1.7.9.1
--
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