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usbcore: refine warm reset logic
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Current waiting time for warm(BH) reset in hub_port_warm_reset() is too short
for xHC host to complete the warm reset and report a BH reset change.

This patch increases the waiting time for warm reset and merges the function
into hub_port_reset(), so it can handle both cold reset and warm reset, and
factor out hub_port_finish_reset() to make the code looks cleaner.

This fixes the issue that driver fails to clear BH reset change and port is
"dead".

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Andiry Xu authored and Greg Kroah-Hartman committed Sep 20, 2011
1 parent d782659 commit 75d7cf7
Showing 1 changed file with 112 additions and 104 deletions.
216 changes: 112 additions & 104 deletions drivers/usb/core/hub.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2025,11 +2025,12 @@ static unsigned hub_is_wusb(struct usb_hub *hub)

#define HUB_ROOT_RESET_TIME 50 /* times are in msec */
#define HUB_SHORT_RESET_TIME 10
#define HUB_BH_RESET_TIME 50
#define HUB_LONG_RESET_TIME 200
#define HUB_RESET_TIMEOUT 500

static int hub_port_wait_reset(struct usb_hub *hub, int port1,
struct usb_device *udev, unsigned int delay)
struct usb_device *udev, unsigned int delay, bool warm)
{
int delay_time, ret;
u16 portstatus;
Expand All @@ -2046,145 +2047,151 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1,
if (ret < 0)
return ret;

/* Device went away? */
if (!(portstatus & USB_PORT_STAT_CONNECTION))
return -ENOTCONN;

/* bomb out completely if the connection bounced */
if ((portchange & USB_PORT_STAT_C_CONNECTION))
return -ENOTCONN;

/* if we`ve finished resetting, then break out of the loop */
if (!(portstatus & USB_PORT_STAT_RESET) &&
(portstatus & USB_PORT_STAT_ENABLE)) {
if (hub_is_wusb(hub))
udev->speed = USB_SPEED_WIRELESS;
else if (hub_is_superspeed(hub->hdev))
udev->speed = USB_SPEED_SUPER;
else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
udev->speed = USB_SPEED_HIGH;
else if (portstatus & USB_PORT_STAT_LOW_SPEED)
udev->speed = USB_SPEED_LOW;
else
udev->speed = USB_SPEED_FULL;
return 0;
/*
* Some buggy devices require a warm reset to be issued even
* when the port appears not to be connected.
*/
if (!warm) {
/* Device went away? */
if (!(portstatus & USB_PORT_STAT_CONNECTION))
return -ENOTCONN;

/* bomb out completely if the connection bounced */
if ((portchange & USB_PORT_STAT_C_CONNECTION))
return -ENOTCONN;

/* if we`ve finished resetting, then break out of
* the loop
*/
if (!(portstatus & USB_PORT_STAT_RESET) &&
(portstatus & USB_PORT_STAT_ENABLE)) {
if (hub_is_wusb(hub))
udev->speed = USB_SPEED_WIRELESS;
else if (hub_is_superspeed(hub->hdev))
udev->speed = USB_SPEED_SUPER;
else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
udev->speed = USB_SPEED_HIGH;
else if (portstatus & USB_PORT_STAT_LOW_SPEED)
udev->speed = USB_SPEED_LOW;
else
udev->speed = USB_SPEED_FULL;
return 0;
}
} else {
if (portchange & USB_PORT_STAT_C_BH_RESET)
return 0;
}

/* switch to the long delay after two short delay failures */
if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
delay = HUB_LONG_RESET_TIME;

dev_dbg (hub->intfdev,
"port %d not reset yet, waiting %dms\n",
port1, delay);
"port %d not %sreset yet, waiting %dms\n",
port1, warm ? "warm " : "", delay);
}

return -EBUSY;
}

static void hub_port_finish_reset(struct usb_hub *hub, int port1,
struct usb_device *udev, int *status, bool warm)
{
switch (*status) {
case 0:
if (!warm) {
struct usb_hcd *hcd;
/* TRSTRCY = 10 ms; plus some extra */
msleep(10 + 40);
update_devnum(udev, 0);
hcd = bus_to_hcd(udev->bus);
if (hcd->driver->reset_device) {
*status = hcd->driver->reset_device(hcd, udev);
if (*status < 0) {
dev_err(&udev->dev, "Cannot reset "
"HCD device state\n");
break;
}
}
}
/* FALL THROUGH */
case -ENOTCONN:
case -ENODEV:
clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_C_RESET);
/* FIXME need disconnect() for NOTATTACHED device */
if (warm) {
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_BH_PORT_RESET);
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_PORT_LINK_STATE);
} else {
usb_set_device_state(udev, *status
? USB_STATE_NOTATTACHED
: USB_STATE_DEFAULT);
}
break;
}
}

/* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
static int hub_port_reset(struct usb_hub *hub, int port1,
struct usb_device *udev, unsigned int delay)
struct usb_device *udev, unsigned int delay, bool warm)
{
int i, status;
struct usb_hcd *hcd;

hcd = bus_to_hcd(udev->bus);
/* Block EHCI CF initialization during the port reset.
* Some companion controllers don't like it when they mix.
*/
down_read(&ehci_cf_port_reset_rwsem);
if (!warm) {
/* Block EHCI CF initialization during the port reset.
* Some companion controllers don't like it when they mix.
*/
down_read(&ehci_cf_port_reset_rwsem);
} else {
if (!hub_is_superspeed(hub->hdev)) {
dev_err(hub->intfdev, "only USB3 hub support "
"warm reset\n");
return -EINVAL;
}
}

/* Reset the port */
for (i = 0; i < PORT_RESET_TRIES; i++) {
status = set_port_feature(hub->hdev,
port1, USB_PORT_FEAT_RESET);
if (status)
status = set_port_feature(hub->hdev, port1, (warm ?
USB_PORT_FEAT_BH_PORT_RESET :
USB_PORT_FEAT_RESET));
if (status) {
dev_err(hub->intfdev,
"cannot reset port %d (err = %d)\n",
port1, status);
else {
status = hub_port_wait_reset(hub, port1, udev, delay);
"cannot %sreset port %d (err = %d)\n",
warm ? "warm " : "", port1, status);
} else {
status = hub_port_wait_reset(hub, port1, udev, delay,
warm);
if (status && status != -ENOTCONN)
dev_dbg(hub->intfdev,
"port_wait_reset: err = %d\n",
status);
}

/* return on disconnect or reset */
switch (status) {
case 0:
/* TRSTRCY = 10 ms; plus some extra */
msleep(10 + 40);
update_devnum(udev, 0);
if (hcd->driver->reset_device) {
status = hcd->driver->reset_device(hcd, udev);
if (status < 0) {
dev_err(&udev->dev, "Cannot reset "
"HCD device state\n");
break;
}
}
/* FALL THROUGH */
case -ENOTCONN:
case -ENODEV:
clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_C_RESET);
/* FIXME need disconnect() for NOTATTACHED device */
usb_set_device_state(udev, status
? USB_STATE_NOTATTACHED
: USB_STATE_DEFAULT);
if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
hub_port_finish_reset(hub, port1, udev, &status, warm);
goto done;
}

dev_dbg (hub->intfdev,
"port %d not enabled, trying reset again...\n",
port1);
"port %d not enabled, trying %sreset again...\n",
port1, warm ? "warm " : "");
delay = HUB_LONG_RESET_TIME;
}

dev_err (hub->intfdev,
"Cannot enable port %i. Maybe the USB cable is bad?\n",
port1);

done:
up_read(&ehci_cf_port_reset_rwsem);
return status;
}

/* Warm reset a USB3 protocol port */
static int hub_port_warm_reset(struct usb_hub *hub, int port)
{
int ret;
u16 portstatus, portchange;

if (!hub_is_superspeed(hub->hdev)) {
dev_err(hub->intfdev, "only USB3 hub support warm reset\n");
return -EINVAL;
}

/* Warm reset the port */
ret = set_port_feature(hub->hdev,
port, USB_PORT_FEAT_BH_PORT_RESET);
if (ret) {
dev_err(hub->intfdev, "cannot warm reset port %d\n", port);
return ret;
}

msleep(20);
ret = hub_port_status(hub, port, &portstatus, &portchange);

if (portchange & USB_PORT_STAT_C_RESET)
clear_port_feature(hub->hdev, port, USB_PORT_FEAT_C_RESET);

if (portchange & USB_PORT_STAT_C_BH_RESET)
clear_port_feature(hub->hdev, port,
USB_PORT_FEAT_C_BH_PORT_RESET);

if (portchange & USB_PORT_STAT_C_LINK_STATE)
clear_port_feature(hub->hdev, port,
USB_PORT_FEAT_C_PORT_LINK_STATE);
done:
if (!warm)
up_read(&ehci_cf_port_reset_rwsem);

return ret;
return status;
}

/* Check if a port is power on */
Expand Down Expand Up @@ -2814,7 +2821,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,

/* Reset the device; full speed may morph to high speed */
/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
retval = hub_port_reset(hub, port1, udev, delay);
retval = hub_port_reset(hub, port1, udev, delay, false);
if (retval < 0) /* error or disconnect */
goto fail;
/* success, speed is known */
Expand Down Expand Up @@ -2935,7 +2942,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
buf->bMaxPacketSize0;
kfree(buf);

retval = hub_port_reset(hub, port1, udev, delay);
retval = hub_port_reset(hub, port1, udev, delay, false);
if (retval < 0) /* error or disconnect */
goto fail;
if (oldspeed != udev->speed) {
Expand Down Expand Up @@ -3556,7 +3563,8 @@ static void hub_events(void)
(portstatus & USB_PORT_STAT_LINK_STATE)
== USB_SS_PORT_LS_SS_INACTIVE) {
dev_dbg(hub_dev, "warm reset port %d\n", i);
hub_port_warm_reset(hub, i);
hub_port_reset(hub, i, NULL,
HUB_BH_RESET_TIME, true);
}

if (connect_change)
Expand Down

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