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_INTRTXE results in an 32bit read
access which also reads INTRRX and therefore may lose interrupts.
This patch uses a shadow register of MUSB_INTRTXE 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 | 2 +-
drivers/usb/musb/musb_gadget.c | 17 +++++++----------
drivers/usb/musb/musb_host.c | 2 +-
4 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 3065618..78037bf 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -694,7 +694,8 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
if (is_peripheral_active(musb)) {
/* REVISIT HNP; just force disconnect */
}
- musb_writew(musb->mregs, MUSB_INTRTXE, musb->epmask);
+ musb->intrtxe = musb->epmask;
+ musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
musb->intrrxe = musb->epmask & 0xfffe;
musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
musb_writeb(musb->mregs, MUSB_INTRUSBE, 0xf7);
@@ -917,7 +918,8 @@ void musb_start(struct musb *musb)
dev_dbg(musb->controller, "<== devctl %02x\n", devctl);
/* Set INT enable registers, enable interrupts */
- musb_writew(regs, MUSB_INTRTXE, musb->epmask);
+ musb->intrtxe = musb->epmask;
+ musb_writew(regs, MUSB_INTRTXE, musb->intrtxe);
musb->intrrxe = musb->epmask & 0xfffe;
musb_writew(regs, MUSB_INTRRXE, musb->intrrxe);
musb_writeb(regs, MUSB_INTRUSBE, 0xf7);
@@ -957,6 +959,7 @@ static void musb_generic_disable(struct musb *musb)
/* disable interrupts */
musb_writeb(mbase, MUSB_INTRUSBE, 0);
+ musb->intrtxe = 0;
musb_writew(mbase, MUSB_INTRTXE, 0);
musb->intrrxe = 0;
musb_writew(mbase, MUSB_INTRRXE, 0);
@@ -2094,7 +2097,6 @@ static void musb_save_context(struct musb *musb)
musb->context.testmode = musb_readb(musb_base, MUSB_TESTMODE);
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.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);
@@ -2167,7 +2169,7 @@ static void musb_restore_context(struct musb *musb)
musb_writeb(musb_base, MUSB_TESTMODE, musb->context.testmode);
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_INTRTXE, musb->intrtxe);
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 3e179ad..7fb4819 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -288,7 +288,6 @@ struct musb_csr_regs {
struct musb_context_registers {
u8 power;
- u16 intrtxe;
u8 intrusbe;
u16 frame;
u8 index, testmode;
@@ -314,6 +313,7 @@ struct musb {
u16 hwvers;
u16 intrrxe;
+ u16 intrtxe;
/* 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 bb684f0..28b9790 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1068,7 +1068,6 @@ static int musb_gadget_enable(struct usb_ep *ep,
*/
musb_ep_select(mbase, epnum);
if (usb_endpoint_dir_in(desc)) {
- u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
if (hw_ep->is_shared_fifo)
musb_ep->is_in = 1;
@@ -1080,8 +1079,8 @@ static int musb_gadget_enable(struct usb_ep *ep,
goto fail;
}
- int_txe |= (1 << epnum);
- musb_writew(mbase, MUSB_INTRTXE, int_txe);
+ musb->intrtxe |= (1 << epnum);
+ musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
/* REVISIT if can_bulk_split(), use by updating "tmp";
* likewise high bandwidth periodic tx
@@ -1208,9 +1207,8 @@ static int musb_gadget_disable(struct usb_ep *ep)
/* zero the endpoint sizes */
if (musb_ep->is_in) {
- u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
- int_txe &= ~(1 << epnum);
- musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
+ musb->intrtxe &= ~(1 << epnum);
+ musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
musb_writew(epio, MUSB_TXMAXP, 0);
} else {
musb->intrrxe &= ~(1 << epnum);
@@ -1530,7 +1528,7 @@ static void musb_gadget_fifo_flush(struct usb_ep *ep)
void __iomem *epio = musb->endpoints[epnum].regs;
void __iomem *mbase;
unsigned long flags;
- u16 csr, int_txe;
+ u16 csr;
mbase = musb->mregs;
@@ -1538,8 +1536,7 @@ static void musb_gadget_fifo_flush(struct usb_ep *ep)
musb_ep_select(mbase, (u8) epnum);
/* disable interrupts */
- int_txe = musb_readw(mbase, MUSB_INTRTXE);
- musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
+ musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe & ~(1 << epnum));
if (musb_ep->is_in) {
csr = musb_readw(epio, MUSB_TXCSR);
@@ -1563,7 +1560,7 @@ static void musb_gadget_fifo_flush(struct usb_ep *ep)
}
/* re-enable interrupt */
- musb_writew(mbase, MUSB_INTRTXE, int_txe);
+ musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
spin_unlock_irqrestore(&musb->lock, flags);
}
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 3df6a76..e9f0fd9 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -740,7 +740,7 @@ static void musb_ep_program(struct musb *musb, u8 epnum,
csr = musb_readw(epio, MUSB_TXCSR);
/* disable interrupt in case we flush */
- int_txe = musb_readw(mbase, MUSB_INTRTXE);
+ int_txe = musb->intrtxe;
musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
/* general endpoint setup */
--
1.7.10.4
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