>From 72d9779f9358a75bd63b47b9d79b8f66db94d682 Mon Sep 17 00:00:00 2001
From: Alek Du <alek.du@xxxxxxxxx>
Date: Tue, 11 May 2010 11:33:19 +0800
Subject: [PATCH 3/3] EHCI: EHCI 1.1 addendum: Enable Per-port change detect bits
This patch will enable Per-port event feature defined in EHCI 1.1
addendum. This feature addresses an issue where HCD is currently
required to read and parse PORTSC for all enabled root hub ports. With
this patch, the overhead will be reduced.
Signed-off-by: Alek Du <alek.du@xxxxxxxxx>
---
drivers/usb/host/ehci-hcd.c | 19 +++++++++++++++++--
drivers/usb/host/ehci-hub.c | 9 +++++++++
drivers/usb/host/ehci.h | 1 +
3 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index e509288..0d9e343 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -584,6 +584,11 @@ static int ehci_init(struct usb_hcd *hcd)
if (log2_irq_thresh < 0 || log2_irq_thresh > 6)
log2_irq_thresh = 0;
temp = 1 << (16 + log2_irq_thresh);
+ if (HCC_PER_PORT_CHANGE_EVENT(hcc_params)) {
+ ehci->has_ppcd = 1;
+ ehci_dbg(ehci, "enable per-port change event\n");
+ temp |= CMD_PPCEE;
+ }
if (HCC_CANPARK(hcc_params)) {
/* HW default park == 3, on hardware that supports it (like
* NVidia and ALI silicon), maximizes throughput on the async
@@ -782,6 +787,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
/* remote wakeup [4.3.1] */
if (status & STS_PCD) {
unsigned i = HCS_N_PORTS (ehci->hcs_params);
+ u32 ppcd = 0;
/* kick root hub later */
pcd_status = status;
@@ -790,9 +796,18 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
if (!(cmd & CMD_RUN))
usb_hcd_resume_root_hub(hcd);
+ /* get per-port change detect bits and will clear them later */
+ if (ehci->has_ppcd)
+ ppcd = status >> 16;
+
while (i--) {
- int pstatus = ehci_readl(ehci,
- &ehci->regs->port_status [i]);
+ int pstatus;
+
+ /* leverage per-port change bits feature */
+ if (ehci->has_ppcd && !(ppcd & (1 << i)))
+ continue;
+ pstatus = ehci_readl(ehci,
+ &ehci->regs->port_status[i]);
if (pstatus & PORT_OWNER)
continue;
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 2c8e71f..f9d119f 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -600,6 +600,7 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
u32 mask;
int ports, i, retval = 1;
unsigned long flags;
+ u32 ppcd = 0;
/* if !USB_SUSPEND, root hub timers won't get shut down ... */
if (!HC_IS_RUNNING(hcd->state))
@@ -629,7 +630,15 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
/* port N changes (bit N)? */
spin_lock_irqsave (&ehci->lock, flags);
+ /* get per-port change detect bits and clear them */
+ if (ehci->has_ppcd) {
+ ppcd = ehci_readl(ehci, &ehci->regs->status) >> 16;
+ ehci_writel(ehci, ppcd << 16, &ehci->regs->status);
+ }
for (i = 0; i < ports; i++) {
+ /* leverage per-port change bits feature */
+ if (ehci->has_ppcd && !(ppcd & (1 << i)))
+ continue;
temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
/*
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 18fa7f9..1158d4a 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -141,6 +141,7 @@ struct ehci_hcd { /* one per controller */
__hc32 *ohci_hcctrl_reg;
unsigned has_hostpc:1;
unsigned has_lpm:1; /* support link power management */
+ unsigned has_ppcd:1; /* support per-port change bits */
u8 sbrn; /* packed release number */
--
1.7.0.4
--
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