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_core.h | 3 ++-
drivers/usb/musb/musb_gadget.c | 10 ++++------
3 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 84a46b5..3065618 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -695,7 +695,8 @@ 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->intrrxe = musb->epmask & 0xfffe;
+ musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
musb_writeb(musb->mregs, MUSB_INTRUSBE, 0xf7);
musb->port1_status &= ~(USB_PORT_STAT_LOW_SPEED
|USB_PORT_STAT_HIGH_SPEED
@@ -917,7 +918,8 @@ 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->intrrxe = musb->epmask & 0xfffe;
+ musb_writew(regs, MUSB_INTRRXE, musb->intrrxe);
musb_writeb(regs, MUSB_INTRUSBE, 0xf7);
musb_writeb(regs, MUSB_TESTMODE, 0);
@@ -956,6 +958,7 @@ static void musb_generic_disable(struct musb *musb)
/* disable interrupts */
musb_writeb(mbase, MUSB_INTRUSBE, 0);
musb_writew(mbase, MUSB_INTRTXE, 0);
+ musb->intrrxe = 0;
musb_writew(mbase, MUSB_INTRRXE, 0);
/* off */
@@ -2092,7 +2095,6 @@ static void musb_save_context(struct musb *musb)
musb->context.busctl = musb_read_ulpi_buscontrol(musb->mregs);
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);
@@ -2166,7 +2168,7 @@ static void musb_restore_context(struct musb *musb)
musb_write_ulpi_buscontrol(musb->mregs, musb->context.busctl);
musb_writeb(musb_base, MUSB_POWER, musb->context.power);
musb_writew(musb_base, MUSB_INTRTXE, musb->context.intrtxe);
- musb_writew(musb_base, MUSB_INTRRXE, musb->context.intrrxe);
+ musb_writew(musb_base, MUSB_INTRRXE, musb->intrrxe);
musb_writeb(musb_base, MUSB_INTRUSBE, musb->context.intrusbe);
musb_writeb(musb_base, MUSB_DEVCTL, musb->context.devctl);
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index 4e9cf4e..3e179ad 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -288,7 +288,7 @@ struct musb_csr_regs {
struct musb_context_registers {
u8 power;
- u16 intrtxe, intrrxe;
+ u16 intrtxe;
u8 intrusbe;
u16 frame;
u8 index, testmode;
@@ -313,6 +313,7 @@ struct musb {
struct work_struct irq_work;
u16 hwvers;
+ u16 intrrxe;
/* this hub status bit is reserved by USB 2.0 and not seen by usbcore */
#define MUSB_PORT_STAT_RESUME (1 << 31)
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index b430f15..bb684f0 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1108,7 +1108,6 @@ 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;
@@ -1120,8 +1119,8 @@ static int musb_gadget_enable(struct usb_ep *ep,
goto fail;
}
- int_rxe |= (1 << epnum);
- musb_writew(mbase, MUSB_INTRRXE, int_rxe);
+ musb->intrrxe |= (1 << epnum);
+ musb_writew(mbase, MUSB_INTRRXE, musb->intrrxe);
/* REVISIT if can_bulk_combine() use by updating "tmp"
* likewise high bandwidth periodic rx
@@ -1214,9 +1213,8 @@ 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->intrrxe &= ~(1 << epnum);
+ musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
musb_writew(epio, MUSB_RXMAXP, 0);
}
--
1.7.10.4
--
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