Commit 10f6524a authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
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[PATCH] USB: EHCI port tweaks 



One change may improve some S1 or S3 resume cases, and the other
seems mostly to explain some strange state "lsusb" would show.
Two fixes:

  - On resume, don't think about resuming any unpowered port, or
    resetting any port with OWNER set to the OHCI/UHCI companion.
    This will make some S1 and S3 resume scenarios work better.

  - PORT_CSC was not being cleared correctly in ehci_hub_status_data.
    This was visible at least through current versions of "lsusb",
    and might have caused some other hub related strangeness.

    The fix addresses all three write-to-clear bits, using the same
    approach that UHCI happens to use:  a mask of bits that are
    cleared in most writes to that port status register.

Original patch seems to have been from from William.Morrow@amd.com
and this version (from David) finishes the write-to-clear changes.

Signed-off-by: default avatarJordan Crouse <jordan.crouse@amd.com>
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 198b9517

drivers/usb/host/ehci-hcd.c

+6 −2
Original line number Diff line number Diff line
@@ -759,12 +759,16 @@ static int ehci_resume (struct usb_hcd *hcd) 
	if (time_before (jiffies, ehci->next_statechange))

		msleep (100);



	/* If any port is suspended, we know we can/must resume the HC. */

	/* If any port is suspended (or owned by the companion),

	 * we know we can/must resume the HC (and mustn't reset it).

	 */

	for (port = HCS_N_PORTS (ehci->hcs_params); port > 0; ) {

		u32	status;

		port--;

		status = readl (&ehci->regs->port_status [port]);

		if (status & PORT_SUSPEND) {

		if (!(status & PORT_POWER))

			continue;

		if (status & (PORT_SUSPEND | PORT_OWNER)) {

			down (&hcd->self.root_hub->serialize);

			retval = ehci_hub_resume (hcd);

			up (&hcd->self.root_hub->serialize);

drivers/usb/host/ehci-hub.c

+16 −11
Original line number Diff line number Diff line
@@ -54,7 +54,7 @@ static int ehci_hub_suspend (struct usb_hcd *hcd) 
	/* suspend any active/unsuspended ports, maybe allow wakeup */

	while (port--) {

		u32 __iomem	*reg = &ehci->regs->port_status [port];

		u32		t1 = readl (reg);

		u32		t1 = readl (reg) & ~PORT_RWC_BITS;

		u32		t2 = t1;



		if ((t1 & PORT_PE) && !(t1 & PORT_OWNER))
@@ -115,7 +115,8 @@ static int ehci_hub_resume (struct usb_hcd *hcd) 
	i = HCS_N_PORTS (ehci->hcs_params);

	while (i--) {

		temp = readl (&ehci->regs->port_status [i]);

		temp &= ~(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E);

		temp &= ~(PORT_RWC_BITS

			| PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E);

		if (temp & PORT_SUSPEND) {

			ehci->reset_done [i] = jiffies + msecs_to_jiffies (20);

			temp |= PORT_RESUME;
@@ -128,7 +129,7 @@ static int ehci_hub_resume (struct usb_hcd *hcd) 
		temp = readl (&ehci->regs->port_status [i]);

		if ((temp & PORT_SUSPEND) == 0)

			continue;

		temp &= ~PORT_RESUME;

		temp &= ~(PORT_RWC_BITS | PORT_RESUME);

		writel (temp, &ehci->regs->port_status [i]);

		ehci_vdbg (ehci, "resumed port %d\n", i + 1);

	}
@@ -191,6 +192,7 @@ static int check_reset_complete ( 


		// what happens if HCS_N_CC(params) == 0 ?

		port_status |= PORT_OWNER;

		port_status &= ~PORT_RWC_BITS;

		writel (port_status, &ehci->regs->port_status [index]);



	} else
@@ -233,7 +235,8 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf) 
		if (temp & PORT_OWNER) {

			/* don't report this in GetPortStatus */

			if (temp & PORT_CSC) {

				temp &= ~PORT_CSC;

				temp &= ~PORT_RWC_BITS;

				temp |= PORT_CSC;

				writel (temp, &ehci->regs->port_status [i]);

			}

			continue;
@@ -343,7 +346,7 @@ static int ehci_hub_control ( 
				&ehci->regs->port_status [wIndex]);

			break;

		case USB_PORT_FEAT_C_ENABLE:

			writel (temp | PORT_PEC,

			writel((temp & ~PORT_RWC_BITS) | PORT_PEC,

				&ehci->regs->port_status [wIndex]);

			break;

		case USB_PORT_FEAT_SUSPEND:
@@ -353,7 +356,8 @@ static int ehci_hub_control ( 
				if ((temp & PORT_PE) == 0)

					goto error;

				/* resume signaling for 20 msec */

				writel ((temp & ~PORT_WAKE_BITS) | PORT_RESUME,

				temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);

				writel (temp | PORT_RESUME,

					&ehci->regs->port_status [wIndex]);

				ehci->reset_done [wIndex] = jiffies

						+ msecs_to_jiffies (20);
@@ -364,15 +368,15 @@ static int ehci_hub_control ( 
			break;

		case USB_PORT_FEAT_POWER:

			if (HCS_PPC (ehci->hcs_params))

				writel (temp & ~PORT_POWER,

				writel (temp & ~(PORT_RWC_BITS | PORT_POWER),

					&ehci->regs->port_status [wIndex]);

			break;

		case USB_PORT_FEAT_C_CONNECTION:

			writel (temp | PORT_CSC,

			writel((temp & ~PORT_RWC_BITS) | PORT_CSC,

				&ehci->regs->port_status [wIndex]);

			break;

		case USB_PORT_FEAT_C_OVER_CURRENT:

			writel (temp | PORT_OCC,

			writel((temp & ~PORT_RWC_BITS) | PORT_OCC,

				&ehci->regs->port_status [wIndex]);

			break;

		case USB_PORT_FEAT_C_RESET:
@@ -416,7 +420,7 @@ static int ehci_hub_control ( 


			/* stop resume signaling */

			temp = readl (&ehci->regs->port_status [wIndex]);

			writel (temp & ~PORT_RESUME,

			writel (temp & ~(PORT_RWC_BITS | PORT_RESUME),

				&ehci->regs->port_status [wIndex]);

			retval = handshake (

					&ehci->regs->port_status [wIndex],
@@ -437,7 +441,7 @@ static int ehci_hub_control ( 
			ehci->reset_done [wIndex] = 0;



			/* force reset to complete */

			writel (temp & ~PORT_RESET,

			writel (temp & ~(PORT_RWC_BITS | PORT_RESET),

					&ehci->regs->port_status [wIndex]);

			/* REVISIT:  some hardware needs 550+ usec to clear

			 * this bit; seems too long to spin routinely...
@@ -500,6 +504,7 @@ static int ehci_hub_control ( 
		if (temp & PORT_OWNER)

			break;



		temp &= ~PORT_RWC_BITS;

		switch (wValue) {

		case USB_PORT_FEAT_SUSPEND:

			if ((temp & PORT_PE) == 0

drivers/usb/host/ehci.h

+1 −0
Original line number Diff line number Diff line
@@ -263,6 +263,7 @@ struct ehci_regs { 
#define PORT_PE		(1<<2)		/* port enable */

#define PORT_CSC	(1<<1)		/* connect status change */

#define PORT_CONNECT	(1<<0)		/* device connected */

#define PORT_RWC_BITS   (PORT_CSC | PORT_PEC | PORT_OCC)

} __attribute__ ((packed));



/* Appendix C, Debug port ... intended for use with special "debug devices"

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