[Quantal][SRU][PATCH 2/2] usb: xhci: add USB2 Link power management BESL support
Gavin Guo
gavin.guo at canonical.com
Wed Sep 25 14:27:40 UTC 2013
From: Mathias Nyman <mathias.nyman at linux.intel.com>
BugLink: https://bugs.launchpad.net/bugs/1229576
usb 2.0 devices with link power managment (LPM) can describe their idle link
timeouts either in BESL or HIRD format, so far xHCI has only supported HIRD but
later xHCI errata add BESL support as well
BESL timeouts need to inform exit latency changes with an evaluate
context command the same way USB 3.0 link PM code does.
The same xhci_change_max_exit_latency() function is used as with USB3
but code is pulled out from #ifdef CONFIG_PM as USB2.0 BESL LPM
funcionality does not depend on CONFIG_PM.
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp at linux.intel.com>
(backported from commit a558ccdcc71c7770c5e80c926a31cfe8a3892a09)
Signed-off-by: Shawn Wang <shawn.wang at canonical.com>
Signed-off-by: Gavin Guo <gavin.guo at canonical.com>
Conflicts:
drivers/usb/host/xhci.c
---
drivers/usb/host/xhci.c | 201 ++++++++++++++++++++++++++++++++---------------
drivers/usb/host/xhci.h | 21 +++++
2 files changed, 158 insertions(+), 64 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index c3b0f2d..fb2aaaf 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3783,6 +3783,56 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
return 0;
}
+/*
+ * Issue an Evaluate Context command to change the Maximum Exit Latency in the
+ * slot context. If that succeeds, store the new MEL in the xhci_virt_device.
+ */
+static int xhci_change_max_exit_latency(struct xhci_hcd *xhci,
+ struct usb_device *udev, u16 max_exit_latency)
+{
+ struct xhci_virt_device *virt_dev;
+ struct xhci_command *command;
+ struct xhci_input_control_ctx *ctrl_ctx;
+ struct xhci_slot_ctx *slot_ctx;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&xhci->lock, flags);
+ if (max_exit_latency == xhci->devs[udev->slot_id]->current_mel) {
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ return 0;
+ }
+
+ /* Attempt to issue an Evaluate Context command to change the MEL. */
+ virt_dev = xhci->devs[udev->slot_id];
+ command = xhci->lpm_command;
+ xhci_slot_copy(xhci, command->in_ctx, virt_dev->out_ctx);
+ spin_unlock_irqrestore(&xhci->lock, flags);
+
+ ctrl_ctx = xhci_get_input_control_ctx(xhci, command->in_ctx);
+ ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
+ slot_ctx = xhci_get_slot_ctx(xhci, command->in_ctx);
+ slot_ctx->dev_info2 &= cpu_to_le32(~((u32) MAX_EXIT));
+ slot_ctx->dev_info2 |= cpu_to_le32(max_exit_latency);
+
+ xhci_dbg(xhci, "Set up evaluate context for LPM MEL change.\n");
+ xhci_dbg(xhci, "Slot %u Input Context:\n", udev->slot_id);
+ xhci_dbg_ctx(xhci, command->in_ctx, 0);
+
+ /* Issue and wait for the evaluate context command. */
+ ret = xhci_configure_endpoint(xhci, udev, command,
+ true, true);
+ xhci_dbg(xhci, "Slot %u Output Context:\n", udev->slot_id);
+ xhci_dbg_ctx(xhci, virt_dev->out_ctx, 0);
+
+ if (!ret) {
+ spin_lock_irqsave(&xhci->lock, flags);
+ virt_dev->current_mel = max_exit_latency;
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ }
+ return ret;
+}
+
#ifdef CONFIG_USB_SUSPEND
/* BESL to HIRD Encoding array for USB2 LPM */
@@ -3824,6 +3874,28 @@ static int xhci_calculate_hird_besl(struct xhci_hcd *xhci,
return besl;
}
+/* Calculate BESLD, L1 timeout and HIRDM for USB2 PORTHLPMC */
+static int xhci_calculate_usb2_hw_lpm_params(struct usb_device *udev)
+{
+ u32 field;
+ int l1;
+ int besld = 0;
+ int hirdm = 0;
+
+ field = le32_to_cpu(udev->bos->ext_cap->bmAttributes);
+
+ /* xHCI l1 is set in steps of 256us, xHCI 1.0 section 5.4.11.2 */
+ l1 = XHCI_L1_TIMEOUT / 256;
+
+ /* device has preferred BESLD */
+ if (field & USB_BESL_DEEP_VALID) {
+ besld = USB_GET_BESL_DEEP(field);
+ hirdm = 1;
+ }
+
+ return PORT_BESLD(besld) | PORT_L1_TIMEOUT(l1) | PORT_HIRDM(hirdm);
+}
+
static int xhci_usb2_software_lpm_test(struct usb_hcd *hcd,
struct usb_device *udev)
{
@@ -3955,11 +4027,12 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
__le32 __iomem **port_array;
- __le32 __iomem *pm_addr;
- u32 temp;
+ __le32 __iomem *pm_addr, *hlpm_addr;
+ u32 pm_val, hlpm_val, field;
unsigned int port_num;
unsigned long flags;
- int hird;
+ int hird, exit_latency;
+ int ret;
if (hcd->speed == HCD_USB3 || !xhci->hw_lpm_support ||
!udev->lpm_capable)
@@ -3977,23 +4050,73 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
port_array = xhci->usb2_ports;
port_num = udev->portnum - 1;
pm_addr = port_array[port_num] + PORTPMSC;
- temp = xhci_readl(xhci, pm_addr);
+ pm_val = xhci_readl(xhci, pm_addr);
+ hlpm_addr = port_array[port_num] + PORTHLPMC;
+ field = le32_to_cpu(udev->bos->ext_cap->bmAttributes);
xhci_dbg(xhci, "%s port %d USB2 hardware LPM\n",
enable ? "enable" : "disable", port_num);
- hird = xhci_calculate_hird_besl(xhci, udev);
-
if (enable) {
- temp &= ~PORT_HIRD_MASK;
- temp |= PORT_HIRD(hird) | PORT_RWE;
- xhci_writel(xhci, temp, pm_addr);
- temp = xhci_readl(xhci, pm_addr);
- temp |= PORT_HLE;
- xhci_writel(xhci, temp, pm_addr);
+ /* Host supports BESL timeout instead of HIRD */
+ if (udev->usb2_hw_lpm_capable) {
+ /* if device doesn't have a preferred BESL value use a
+ * default one which works with mixed HIRD and BESL
+ * systems. See XHCI_DEFAULT_BESL definition in xhci.h
+ */
+ if ((field & USB_BESL_SUPPORT) &&
+ (field & USB_BESL_BASELINE_VALID))
+ hird = USB_GET_BESL_BASELINE(field);
+ else
+ hird = XHCI_DEFAULT_BESL;
+
+ exit_latency = xhci_besl_encoding[hird];
+ spin_unlock_irqrestore(&xhci->lock, flags);
+
+ /* USB 3.0 code dedicate one xhci->lpm_command->in_ctx
+ * input context for link powermanagement evaluate
+ * context commands. It is protected by hcd->bandwidth
+ * mutex and is shared by all devices. We need to set
+ * the max ext latency in USB 2 BESL LPM as well, so
+ * use the same mutex and xhci_change_max_exit_latency()
+ */
+ mutex_lock(hcd->bandwidth_mutex);
+ ret = xhci_change_max_exit_latency(xhci, udev,
+ exit_latency);
+ mutex_unlock(hcd->bandwidth_mutex);
+
+ if (ret < 0)
+ return ret;
+ spin_lock_irqsave(&xhci->lock, flags);
+
+ hlpm_val = xhci_calculate_usb2_hw_lpm_params(udev);
+ xhci_writel(xhci, hlpm_val, hlpm_addr);
+ /* flush write */
+ xhci_readl(xhci, hlpm_addr);
+ } else {
+ hird = xhci_calculate_hird_besl(xhci, udev);
+ }
+
+ pm_val &= ~PORT_HIRD_MASK;
+ pm_val |= PORT_HIRD(hird) | PORT_RWE;
+ xhci_writel(xhci, pm_val, pm_addr);
+ pm_val = xhci_readl(xhci, pm_addr);
+ pm_val |= PORT_HLE;
+ xhci_writel(xhci, pm_val, pm_addr);
+ /* flush write */
+ xhci_readl(xhci, pm_addr);
} else {
- temp &= ~(PORT_HLE | PORT_RWE | PORT_HIRD_MASK);
- xhci_writel(xhci, temp, pm_addr);
+ pm_val &= ~(PORT_HLE | PORT_RWE | PORT_HIRD_MASK);
+ xhci_writel(xhci, pm_val, pm_addr);
+ /* flush write */
+ xhci_readl(xhci, pm_addr);
+ if (udev->usb2_hw_lpm_capable) {
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ mutex_lock(hcd->bandwidth_mutex);
+ xhci_change_max_exit_latency(xhci, udev, 0);
+ mutex_unlock(hcd->bandwidth_mutex);
+ return 0;
+ }
}
spin_unlock_irqrestore(&xhci->lock, flags);
@@ -4340,56 +4463,6 @@ static u16 xhci_calculate_lpm_timeout(struct usb_hcd *hcd,
return timeout;
}
-/*
- * Issue an Evaluate Context command to change the Maximum Exit Latency in the
- * slot context. If that succeeds, store the new MEL in the xhci_virt_device.
- */
-static int xhci_change_max_exit_latency(struct xhci_hcd *xhci,
- struct usb_device *udev, u16 max_exit_latency)
-{
- struct xhci_virt_device *virt_dev;
- struct xhci_command *command;
- struct xhci_input_control_ctx *ctrl_ctx;
- struct xhci_slot_ctx *slot_ctx;
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&xhci->lock, flags);
- if (max_exit_latency == xhci->devs[udev->slot_id]->current_mel) {
- spin_unlock_irqrestore(&xhci->lock, flags);
- return 0;
- }
-
- /* Attempt to issue an Evaluate Context command to change the MEL. */
- virt_dev = xhci->devs[udev->slot_id];
- command = xhci->lpm_command;
- xhci_slot_copy(xhci, command->in_ctx, virt_dev->out_ctx);
- spin_unlock_irqrestore(&xhci->lock, flags);
-
- ctrl_ctx = xhci_get_input_control_ctx(xhci, command->in_ctx);
- ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
- slot_ctx = xhci_get_slot_ctx(xhci, command->in_ctx);
- slot_ctx->dev_info2 &= cpu_to_le32(~((u32) MAX_EXIT));
- slot_ctx->dev_info2 |= cpu_to_le32(max_exit_latency);
-
- xhci_dbg(xhci, "Set up evaluate context for LPM MEL change.\n");
- xhci_dbg(xhci, "Slot %u Input Context:\n", udev->slot_id);
- xhci_dbg_ctx(xhci, command->in_ctx, 0);
-
- /* Issue and wait for the evaluate context command. */
- ret = xhci_configure_endpoint(xhci, udev, command,
- true, true);
- xhci_dbg(xhci, "Slot %u Output Context:\n", udev->slot_id);
- xhci_dbg_ctx(xhci, virt_dev->out_ctx, 0);
-
- if (!ret) {
- spin_lock_irqsave(&xhci->lock, flags);
- virt_dev->current_mel = max_exit_latency;
- spin_unlock_irqrestore(&xhci->lock, flags);
- }
- return ret;
-}
-
static int calculate_max_exit_latency(struct usb_device *udev,
enum usb3_link_state state_changed,
u16 hub_encoded_timeout)
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 79c324a..5897c13 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -386,6 +386,27 @@ struct xhci_op_regs {
#define PORT_L1DS(p) (((p) & 0xff) << 8)
#define PORT_HLE (1 << 16)
+
+/* USB2 Protocol PORTHLPMC */
+#define PORT_HIRDM(p)((p) & 3)
+#define PORT_L1_TIMEOUT(p)(((p) & 0xff) << 2)
+#define PORT_BESLD(p)(((p) & 0xf) << 10)
+
+/* use 512 microseconds as USB2 LPM L1 default timeout. */
+#define XHCI_L1_TIMEOUT 512
+
+/* Set default HIRD/BESL value to 4 (350/400us) for USB2 L1 LPM resume latency.
+ * Safe to use with mixed HIRD and BESL systems (host and device) and is used
+ * by other operating systems.
+ *
+ * XHCI 1.0 errata 8/14/12 Table 13 notes:
+ * "Software should choose xHC BESL/BESLD field values that do not violate a
+ * device's resume latency requirements,
+ * e.g. not program values > '4' if BLC = '1' and a HIRD device is attached,
+ * or not program values < '4' if BLC = '0' and a BESL device is attached.
+ */
+#define XHCI_DEFAULT_BESL 4
+
/**
* struct xhci_intr_reg - Interrupt Register Set
* @irq_pending: IMAN - Interrupt Management Register. Used to enable
--
1.7.9.5
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