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xhci: prevent U2 link power state if Intel tier policy prevented U1

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Don't enable U1 or U2 Link powermanagenet (LPM) states for USB3
devices connected to tier 2 or further hubs.

For unknown reasons we previously only prevented U1.
Be consistent, and prevent both U1/U2 states if tier policy doesn't
allow LPM.

Also check the tier policy a bit earlier, and return if U1/U2 is
not allowed. This avoids unnecessary xhci MEL commands.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220511220450.85367-8-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2022-05-12 01:04:48 +03:00 committed by Greg Kroah-Hartman
parent 25355e046d
commit 424140d31b
1 changed files with 4 additions and 7 deletions
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11
drivers/usb/host/xhci.c
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@ -4888,9 +4888,6 @@ static int xhci_check_intel_tier_policy(struct usb_device *udev,
struct usb_device *parent;
unsigned int num_hubs;
if (state == USB3_LPM_U2)
return 0;
/* Don't enable U1 if the device is on a 2nd tier hub or lower. */
for (parent = udev->parent, num_hubs = 0; parent->parent;
parent = parent->parent)
@ -4899,7 +4896,7 @@ static int xhci_check_intel_tier_policy(struct usb_device *udev,
if (num_hubs < 2)
return 0;
dev_dbg(&udev->dev, "Disabling U1 link state for device"
dev_dbg(&udev->dev, "Disabling U1/U2 link state for device"
" below second-tier hub.\n");
dev_dbg(&udev->dev, "Plug device into first-tier hub "
"to decrease power consumption.\n");
@ -4940,9 +4937,6 @@ static u16 xhci_calculate_lpm_timeout(struct usb_hcd *hcd,
return timeout;
}
if (xhci_check_tier_policy(xhci, udev, state) < 0)
return timeout;
/* Gather some information about the currently installed configuration
* and alternate interface settings.
*/
@ -5049,6 +5043,9 @@ static int xhci_enable_usb3_lpm_timeout(struct usb_hcd *hcd,
!xhci->devs[udev->slot_id])
return USB3_LPM_DISABLED;
if (xhci_check_tier_policy(xhci, udev, state) < 0)
return USB3_LPM_DISABLED;
hub_encoded_timeout = xhci_calculate_lpm_timeout(hcd, udev, state);
mel = calculate_max_exit_latency(udev, state, hub_encoded_timeout);
if (mel < 0) {