xHCI: BESL calculation based on USB2.0 LPM errata
The latest released errata for USB2.0 ECN LPM adds new fields to USB2.0
extension descriptor, defines two BESL values for device: baseline BESL
and deep BESL. Baseline BESL value communicates a nominal power savings
design point and the deep BESL value communicates a significant power
savings design point.
If device indicates BESL value, driver will use a value count in both
host BESL and device BESL. Use baseline BESL value as default.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Tested-by: Jason Fan <jcfan@qca.qualcomm.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index a629ad8..262400c 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3614,26 +3614,38 @@
3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000};
/* Calculate HIRD/BESL for USB2 PORTPMSC*/
-static int xhci_calculate_hird_besl(int u2del, bool use_besl)
+static int xhci_calculate_hird_besl(struct xhci_hcd *xhci,
+ struct usb_device *udev)
{
- int hird;
+ int u2del, besl, besl_host;
+ int besl_device = 0;
+ u32 field;
- if (use_besl) {
- for (hird = 0; hird < 16; hird++) {
- if (xhci_besl_encoding[hird] >= u2del)
+ u2del = HCS_U2_LATENCY(xhci->hcs_params3);
+ field = le32_to_cpu(udev->bos->ext_cap->bmAttributes);
+
+ if (field & USB_BESL_SUPPORT) {
+ for (besl_host = 0; besl_host < 16; besl_host++) {
+ if (xhci_besl_encoding[besl_host] >= u2del)
break;
}
+ /* Use baseline BESL value as default */
+ if (field & USB_BESL_BASELINE_VALID)
+ besl_device = USB_GET_BESL_BASELINE(field);
+ else if (field & USB_BESL_DEEP_VALID)
+ besl_device = USB_GET_BESL_DEEP(field);
} else {
if (u2del <= 50)
- hird = 0;
+ besl_host = 0;
else
- hird = (u2del - 51) / 75 + 1;
-
- if (hird > 15)
- hird = 15;
+ besl_host = (u2del - 51) / 75 + 1;
}
- return hird;
+ besl = besl_host + besl_device;
+ if (besl > 15)
+ besl = 15;
+
+ return besl;
}
static int xhci_usb2_software_lpm_test(struct usb_hcd *hcd,
@@ -3646,7 +3658,7 @@
u32 temp, dev_id;
unsigned int port_num;
unsigned long flags;
- int u2del, hird;
+ int hird;
int ret;
if (hcd->speed == HCD_USB3 || !xhci->sw_lpm_support ||
@@ -3692,12 +3704,7 @@
* HIRD or BESL shoule be used. See USB2.0 LPM errata.
*/
pm_addr = port_array[port_num] + 1;
- u2del = HCS_U2_LATENCY(xhci->hcs_params3);
- if (le32_to_cpu(udev->bos->ext_cap->bmAttributes) & (1 << 2))
- hird = xhci_calculate_hird_besl(u2del, 1);
- else
- hird = xhci_calculate_hird_besl(u2del, 0);
-
+ hird = xhci_calculate_hird_besl(xhci, udev);
temp = PORT_L1DS(udev->slot_id) | PORT_HIRD(hird);
xhci_writel(xhci, temp, pm_addr);
@@ -3776,7 +3783,7 @@
u32 temp;
unsigned int port_num;
unsigned long flags;
- int u2del, hird;
+ int hird;
if (hcd->speed == HCD_USB3 || !xhci->hw_lpm_support ||
!udev->lpm_capable)
@@ -3799,11 +3806,7 @@
xhci_dbg(xhci, "%s port %d USB2 hardware LPM\n",
enable ? "enable" : "disable", port_num);
- u2del = HCS_U2_LATENCY(xhci->hcs_params3);
- if (le32_to_cpu(udev->bos->ext_cap->bmAttributes) & (1 << 2))
- hird = xhci_calculate_hird_besl(u2del, 1);
- else
- hird = xhci_calculate_hird_besl(u2del, 0);
+ hird = xhci_calculate_hird_besl(xhci, udev);
if (enable) {
temp &= ~PORT_HIRD_MASK;