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Commit af5ec14d authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Felipe Balbi
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usb: musb: Perform only write access on MUSB_INTRRXE 



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: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent 515ba29c

drivers/usb/musb/musb_core.c

+6 −4
Original line number Diff line number Diff line
@@ -725,7 +725,8 @@ 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
@@ -947,7 +948,8 @@ 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);
@@ -986,6 +988,7 @@ 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 */
@@ -2122,7 +2125,6 @@ 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);
@@ -2196,7 +2198,7 @@ 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);

drivers/usb/musb/musb_core.h

+2 −1
Original line number Diff line number Diff line
@@ -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)

drivers/usb/musb/musb_gadget.c

+4 −6
Original line number Diff line number Diff line
@@ -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);

	}