[PATCH] USB: OHCI relies less on NDP register

Some OHCI implementations have differences in the way the NDP register
(in roothub_a) reports the number of ports present. This patch allows the
platform specific code to optionally supply the number of ports. The
driver just reads the value at init (if not supplied) instead of reading
it every time its needed (except for an AMD756 bug workaround).

It also sets the value correctly for the ARM pxa27x architecture.
Signed-Off-By: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/ohci-dbg.c

@@ -228,23 +228,22 @@ ohci_dump_roothub (
 	char **next,
 	unsigned *size)
 {
-	u32			temp, ndp, i;
+	u32			temp, i;
 
 	temp = roothub_a (controller);
 	if (temp == ~(u32)0)
 		return;
-	ndp = (temp & RH_A_NDP);
 
 	if (verbose) {
 		ohci_dbg_sw (controller, next, size,
-			"roothub.a %08x POTPGT=%d%s%s%s%s%s NDP=%d\n", temp,
+			"roothub.a %08x POTPGT=%d%s%s%s%s%s NDP=%d(%d)\n", temp,
 			((temp & RH_A_POTPGT) >> 24) & 0xff,
 			(temp & RH_A_NOCP) ? " NOCP" : "",
 			(temp & RH_A_OCPM) ? " OCPM" : "",
 			(temp & RH_A_DT) ? " DT" : "",
 			(temp & RH_A_NPS) ? " NPS" : "",
 			(temp & RH_A_PSM) ? " PSM" : "",
-			ndp
+			(temp & RH_A_NDP), controller->num_ports
 			);
 		temp = roothub_b (controller);
 		ohci_dbg_sw (controller, next, size,
@@ -266,7 +265,7 @@ ohci_dump_roothub (
 			);
 	}
 
-	for (i = 0; i < ndp; i++) {
+	for (i = 0; i < controller->num_ports; i++) {
 		temp = roothub_portstatus (controller, i);
 		dbg_port_sw (controller, i, temp, next, size);
 	}

drivers/usb/host/ohci-hcd.c

@@ -484,6 +484,10 @@ static int ohci_init (struct ohci_hcd *ohci)
 	// flush the writes
 	(void) ohci_readl (ohci, &ohci->regs->control);
 
+	/* Read the number of ports unless overridden */
+	if (ohci->num_ports == 0)
+		ohci->num_ports = roothub_a(ohci) & RH_A_NDP;
+
 	if (ohci->hcca)
 		return 0;
 
@@ -560,10 +564,8 @@ static int ohci_run (struct ohci_hcd *ohci)
 	msleep(temp);
 	temp = roothub_a (ohci);
 	if (!(temp & RH_A_NPS)) {
-		unsigned ports = temp & RH_A_NDP; 
-
 		/* power down each port */
-		for (temp = 0; temp < ports; temp++)
+		for (temp = 0; temp < ohci->num_ports; temp++)
 			ohci_writel (ohci, RH_PS_LSDA,
 				&ohci->regs->roothub.portstatus [temp]);
 	}
@@ -861,7 +863,7 @@ static int ohci_restart (struct ohci_hcd *ohci)
 		 * and that if we try to turn them back on the root hub
 		 * will respond to CSC processing.
 		 */
-		i = roothub_a (ohci) & RH_A_NDP;
+		i = ohci->num_ports;
 		while (i--)
 			ohci_writel (ohci, RH_PS_PSS,
 				&ohci->regs->roothub.portstatus [temp]);

drivers/usb/host/ohci-hub.c

@@ -184,7 +184,7 @@ static int ohci_hub_resume (struct usb_hcd *hcd)
 	if (status != -EINPROGRESS)
 		return status;
 
-	temp = roothub_a (ohci) & RH_A_NDP;
+	temp = ohci->num_ports;
 	enables = 0;
 	while (temp--) {
 		u32 stat = ohci_readl (ohci,
@@ -304,7 +304,7 @@ static int
 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 {
 	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
-	int		ports, i, changed = 0, length = 1;
+	int		i, changed = 0, length = 1;
 	int		can_suspend = hcd->can_wakeup;
 	unsigned long	flags;
 
@@ -319,9 +319,10 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 		goto done;
 	}
 
-	ports = roothub_a (ohci) & RH_A_NDP; 
-	if (ports > MAX_ROOT_PORTS) {
-		ohci_err (ohci, "bogus NDP=%d, rereads as NDP=%d\n", ports,
+	/* undocumented erratum seen on at least rev D */
+	if ((ohci->flags & OHCI_QUIRK_AMD756)
+			&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
+		ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
 			  ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
 		/* retry later; "should not happen" */
 		goto done;
@@ -332,13 +333,13 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 		buf [0] = changed = 1;
 	else
 		buf [0] = 0;
-	if (ports > 7) {
+	if (ohci->num_ports > 7) {
 		buf [1] = 0;
 		length++;
 	}
 
 	/* look at each port */
-	for (i = 0; i < ports; i++) {
+	for (i = 0; i < ohci->num_ports; i++) {
 		u32	status = roothub_portstatus (ohci, i);
 
 		if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
@@ -395,15 +396,14 @@ ohci_hub_descriptor (
 	struct usb_hub_descriptor	*desc
 ) {
 	u32		rh = roothub_a (ohci);
-	int		ports = rh & RH_A_NDP; 
 	u16		temp;
 
 	desc->bDescriptorType = 0x29;
 	desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
 	desc->bHubContrCurrent = 0;
 
-	desc->bNbrPorts = ports;
-	temp = 1 + (ports / 8);
+	desc->bNbrPorts = ohci->num_ports;
+	temp = 1 + (ohci->num_ports / 8);
 	desc->bDescLength = 7 + 2 * temp;
 
 	temp = 0;
@@ -421,7 +421,7 @@ ohci_hub_descriptor (
 	rh = roothub_b (ohci);
 	memset(desc->bitmap, 0xff, sizeof(desc->bitmap));
 	desc->bitmap [0] = rh & RH_B_DR;
-	if (ports > 7) {
+	if (ohci->num_ports > 7) {
 		desc->bitmap [1] = (rh & RH_B_DR) >> 8;
 		desc->bitmap [2] = 0xff;
 	} else

drivers/usb/host/ohci-pxa27x.c

@@ -258,6 +258,9 @@ ohci_pxa27x_start (struct usb_hcd *hcd)
 
 	ohci_dbg (ohci, "ohci_pxa27x_start, ohci:%p", ohci);
 
+	/* The value of NDP in roothub_a is incorrect on this hardware */
+	ohci->num_ports = 3;
+
 	if ((ret = ohci_init(ohci)) < 0)
 		return ret;
 

drivers/usb/host/ohci.h

@@ -383,6 +383,7 @@ struct ohci_hcd {
 	/*
 	 * driver state
 	 */
+	int			num_ports;
 	int			load [NUM_INTS];
 	u32 			hc_control;	/* copy of hc control reg */
 	unsigned long		next_statechange;	/* suspend/resume */