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authorKai-Heng Feng <kai.heng.feng@canonical.com>2020-03-12 17:45:15 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-04-29 17:33:03 +0300
commitea6f7011c42db70b6380480d0561d8f9402d6f76 (patch)
treed31e7def2bab6708648917dc9aa887d2d893bb69
parente650a264df6f72701874f6eab11fdb28a861515e (diff)
downloadlinux-ea6f7011c42db70b6380480d0561d8f9402d6f76.tar.xz
xhci: Wait until link state trainsits to U0 after setting USB_SS_PORT_LS_U0
[ Upstream commit 0200b9f790b0fc9e9a42f685f5ad54b23fe959f4 ] Like U3 case, xHCI spec doesn't specify the upper bound of U0 transition time. The 20ms is not enough for some devices. Intead of polling PLS or PLC, we can facilitate the port change event to know that the link transits to U0 is completed. While at it, also separate U0 and U3 case to make the code cleaner. [variable rename to u3exit, and skip completion for usb2 ports -Mathias ] Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200312144517.1593-8-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/usb/host/xhci-hub.c44
-rw-r--r--drivers/usb/host/xhci-mem.c1
-rw-r--r--drivers/usb/host/xhci-ring.c1
-rw-r--r--drivers/usb/host/xhci.h1
4 files changed, 34 insertions, 13 deletions
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 712cd44f05ac..02f52d4f74df 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1306,7 +1306,33 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
wIndex, link_state);
goto error;
}
+
+ if (link_state == USB_SS_PORT_LS_U0) {
+ if ((temp & PORT_PLS_MASK) == XDEV_U0)
+ break;
+
+ if (!((temp & PORT_PLS_MASK) == XDEV_U1 ||
+ (temp & PORT_PLS_MASK) == XDEV_U2 ||
+ (temp & PORT_PLS_MASK) == XDEV_U3)) {
+ xhci_warn(xhci, "Can only set port %d to U0 from U state\n",
+ wIndex);
+ goto error;
+ }
+ reinit_completion(&bus_state->u3exit_done[wIndex]);
+ xhci_set_link_state(xhci, ports[wIndex],
+ USB_SS_PORT_LS_U0);
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ if (!wait_for_completion_timeout(&bus_state->u3exit_done[wIndex],
+ msecs_to_jiffies(100)))
+ xhci_dbg(xhci, "missing U0 port change event for port %d\n",
+ wIndex);
+ spin_lock_irqsave(&xhci->lock, flags);
+ temp = readl(ports[wIndex]->addr);
+ break;
+ }
+
if (link_state == USB_SS_PORT_LS_U3) {
+ int retries = 16;
slot_id = xhci_find_slot_id_by_port(hcd, xhci,
wIndex + 1);
if (slot_id) {
@@ -1317,26 +1343,18 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
xhci_stop_device(xhci, slot_id, 1);
spin_lock_irqsave(&xhci->lock, flags);
}
- }
-
- xhci_set_link_state(xhci, ports[wIndex], link_state);
-
- spin_unlock_irqrestore(&xhci->lock, flags);
- if (link_state == USB_SS_PORT_LS_U3) {
- int retries = 16;
-
+ xhci_set_link_state(xhci, ports[wIndex], USB_SS_PORT_LS_U3);
+ spin_unlock_irqrestore(&xhci->lock, flags);
while (retries--) {
usleep_range(4000, 8000);
temp = readl(ports[wIndex]->addr);
if ((temp & PORT_PLS_MASK) == XDEV_U3)
break;
}
- }
- spin_lock_irqsave(&xhci->lock, flags);
-
- temp = readl(ports[wIndex]->addr);
- if (link_state == USB_SS_PORT_LS_U3)
+ spin_lock_irqsave(&xhci->lock, flags);
+ temp = readl(ports[wIndex]->addr);
bus_state->suspended_ports |= 1 << wIndex;
+ }
break;
case USB_PORT_FEAT_POWER:
/*
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 884c601bfa15..9764122c9cdf 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2552,6 +2552,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
xhci->usb3_rhub.bus_state.resume_done[i] = 0;
/* Only the USB 2.0 completions will ever be used. */
init_completion(&xhci->usb2_rhub.bus_state.rexit_done[i]);
+ init_completion(&xhci->usb3_rhub.bus_state.u3exit_done[i]);
}
if (scratchpad_alloc(xhci, flags))
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index f7a190fb2353..a952d99f0456 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1673,6 +1673,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
(portsc & PORT_PLS_MASK) == XDEV_U1 ||
(portsc & PORT_PLS_MASK) == XDEV_U2)) {
xhci_dbg(xhci, "resume SS port %d finished\n", port_id);
+ complete(&bus_state->u3exit_done[hcd_portnum]);
/* We've just brought the device into U0/1/2 through either the
* Resume state after a device remote wakeup, or through the
* U3Exit state after a host-initiated resume. If it's a device
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 98b98a0cd2a8..3ad4f80960d0 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1694,6 +1694,7 @@ struct xhci_bus_state {
/* Which ports are waiting on RExit to U0 transition. */
unsigned long rexit_ports;
struct completion rexit_done[USB_MAXCHILDREN];
+ struct completion u3exit_done[USB_MAXCHILDREN];
};