From f99298bfa7c42da8d27c2b42050941471c0866ab Mon Sep 17 00:00:00 2001 From: Andiry Xu Date: Mon, 12 Dec 2011 16:45:28 +0800 Subject: [PATCH] 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 Tested-by: Jason Fan Signed-off-by: Sarah Sharp --- drivers/usb/host/xhci.c | 51 ++++++++++++++++++++++------------------- include/linux/usb/ch9.h | 5 ++++ 2 files changed, 32 insertions(+), 24 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index a629ad860329..262400c10075 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3614,26 +3614,38 @@ static int xhci_besl_encoding[16] = {125, 150, 200, 300, 400, 500, 1000, 2000, 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; + + u2del = HCS_U2_LATENCY(xhci->hcs_params3); + field = le32_to_cpu(udev->bos->ext_cap->bmAttributes); - if (use_besl) { - for (hird = 0; hird < 16; hird++) { - if (xhci_besl_encoding[hird] >= u2del) + 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 @@ static int xhci_usb2_software_lpm_test(struct usb_hcd *hcd, 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 @@ static int xhci_usb2_software_lpm_test(struct usb_hcd *hcd, * 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 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd, 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 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd, 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; diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h index 3b6f628880f8..af21f3115919 100644 --- a/include/linux/usb/ch9.h +++ b/include/linux/usb/ch9.h @@ -789,6 +789,11 @@ struct usb_ext_cap_descriptor { /* Link Power Management */ __u8 bDevCapabilityType; __le32 bmAttributes; #define USB_LPM_SUPPORT (1 << 1) /* supports LPM */ +#define USB_BESL_SUPPORT (1 << 2) /* supports BESL */ +#define USB_BESL_BASELINE_VALID (1 << 3) /* Baseline BESL valid*/ +#define USB_BESL_DEEP_VALID (1 << 4) /* Deep BESL valid */ +#define USB_GET_BESL_BASELINE(p) (((p) & (0xf << 8)) >> 8) +#define USB_GET_BESL_DEEP(p) (((p) & (0xf << 12)) >> 12) } __attribute__((packed)); #define USB_DT_USB_EXT_CAP_SIZE 7 -- 2.20.1