The ehci-hcd driver is a little haphazard about keeping track of the
state of the USBCMD register. The ehci->command field is supposed to
hold the register's value (apart from a few special bits) at all
times, but it isn't maintained properly.
This patch (as1543) cleans up the situation. It keeps ehci->command
up-to-date, and uses that value rather than reading the register from
the hardware whenever possible.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/ehci-dbg.c | 6 ++----
drivers/usb/host/ehci-hcd.c | 18 +++++++++++-------
drivers/usb/host/ehci-hub.c | 2 +-
drivers/usb/host/ehci-q.c | 16 ++++++----------
drivers/usb/host/ehci-sched.c | 10 ++++------
6 files changed, 29 insertions(+), 37 deletions(-)
Index: usb-3.4/drivers/usb/host/ehci-dbg.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-dbg.c
+++ usb-3.4/drivers/usb/host/ehci-dbg.c
@@ -1032,10 +1032,8 @@ static ssize_t debug_lpm_write(struct fi
if (strict_strtoul(buf + 5, 16, &hird))
return -EINVAL;
printk(KERN_INFO "setting hird %s %lu\n", buf + 6, hird);
- temp = ehci_readl(ehci, &ehci->regs->command);
- temp &= ~CMD_HIRD;
- temp |= hird << 24;
- ehci_writel(ehci, temp, &ehci->regs->command);
+ ehci->command = (ehci->command & ~CMD_HIRD) | (hird << 24);
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
} else if (strncmp(buf, "disable", 7) == 0) {
if (strict_strtoul(buf + 8, 10, &port))
return -EINVAL;
Index: usb-3.4/drivers/usb/host/ehci-hcd.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-hcd.c
+++ usb-3.4/drivers/usb/host/ehci-hcd.c
@@ -226,8 +226,13 @@ static int ehci_halt (struct ehci_hcd *e
if ((temp & STS_HALT) != 0)
return 0;
+ /*
+ * This routine gets called during probe before ehci->command
+ * has been initialized, so we can't rely on its value.
+ */
+ ehci->command &= ~CMD_RUN;
temp = ehci_readl(ehci, &ehci->regs->command);
- temp &= ~CMD_RUN;
+ temp &= ~(CMD_RUN | CMD_IAAD);
ehci_writel(ehci, temp, &ehci->regs->command);
return handshake (ehci, &ehci->regs->status,
STS_HALT, STS_HALT, 16 * 125);
@@ -347,6 +352,7 @@ static int ehci_reset (struct ehci_hcd *
if (ehci->debug)
dbgp_external_startup();
+ ehci->command = ehci_readl(ehci, &ehci->regs->command);
ehci->port_c_suspend = ehci->suspended_ports =
ehci->resuming_ports = 0;
return retval;
@@ -363,16 +369,14 @@ static void ehci_quiesce (struct ehci_hc
#endif
/* wait for any schedule enables/disables to take effect */
- temp = ehci_readl(ehci, &ehci->regs->command) << 10;
- temp &= STS_ASS | STS_PSS;
+ temp = (ehci->command << 10) & (STS_ASS | STS_PSS);
if (handshake_on_error_set_halt(ehci, &ehci->regs->status,
STS_ASS | STS_PSS, temp, 16 * 125))
return;
/* then disable anything that's still active */
- temp = ehci_readl(ehci, &ehci->regs->command);
- temp &= ~(CMD_ASE | CMD_IAAD | CMD_PSE);
- ehci_writel(ehci, temp, &ehci->regs->command);
+ ehci->command &= ~(CMD_ASE | CMD_PSE);
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
/* hardware can take 16 microframes to turn off ... */
handshake_on_error_set_halt(ehci, &ehci->regs->status,
Index: usb-3.4/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-hub.c
+++ usb-3.4/drivers/usb/host/ehci-hub.c
@@ -233,7 +233,6 @@ static int ehci_bus_suspend (struct usb_
/* stop schedules, clean any completed work */
if (ehci->rh_state == EHCI_RH_RUNNING)
ehci_quiesce (ehci);
- ehci->command = ehci_readl(ehci, &ehci->regs->command);
ehci_work(ehci);
/* Unlike other USB host controller types, EHCI doesn't have
@@ -374,6 +373,7 @@ static int ehci_bus_resume (struct usb_h
ehci_writel(ehci, (u32) ehci->async->qh_dma, &ehci->regs->async_next);
/* restore CMD_RUN, framelist size, and irq threshold */
+ ehci->command |= CMD_RUN;
ehci_writel(ehci, ehci->command, &ehci->regs->command);
ehci->rh_state = EHCI_RH_RUNNING;
Index: usb-3.4/drivers/usb/host/ehci-q.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-q.c
+++ usb-3.4/drivers/usb/host/ehci-q.c
@@ -981,14 +981,12 @@ static void qh_link_async (struct ehci_h
head = ehci->async;
timer_action_done (ehci, TIMER_ASYNC_OFF);
if (!head->qh_next.qh) {
- u32 cmd = ehci_readl(ehci, &ehci->regs->command);
-
- if (!(cmd & CMD_ASE)) {
+ if (!(ehci->command & CMD_ASE)) {
/* in case a clear of CMD_ASE didn't take yet */
(void)handshake(ehci, &ehci->regs->status,
STS_ASS, 0, 150);
- cmd |= CMD_ASE;
- ehci_writel(ehci, cmd, &ehci->regs->command);
+ ehci->command |= CMD_ASE;
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
/* posted write need not be known to HC yet ... */
}
}
@@ -1204,7 +1202,6 @@ static void end_unlink_async (struct ehc
static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
{
- int cmd = ehci_readl(ehci, &ehci->regs->command);
struct ehci_qh *prev;
#ifdef DEBUG
@@ -1222,8 +1219,8 @@ static void start_unlink_async (struct e
if (ehci->rh_state != EHCI_RH_HALTED
&& !ehci->reclaim) {
/* ... and CMD_IAAD clear */
- ehci_writel(ehci, cmd & ~CMD_ASE,
- &ehci->regs->command);
+ ehci->command &= ~CMD_ASE;
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
wmb ();
// handshake later, if we need to
timer_action_done (ehci, TIMER_ASYNC_OFF);
@@ -1253,8 +1250,7 @@ static void start_unlink_async (struct e
return;
}
- cmd |= CMD_IAAD;
- ehci_writel(ehci, cmd, &ehci->regs->command);
+ ehci_writel(ehci, ehci->command | CMD_IAAD, &ehci->regs->command);
(void)ehci_readl(ehci, &ehci->regs->command);
iaa_watchdog_start(ehci);
}
Index: usb-3.4/drivers/usb/host/ehci-sched.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-sched.c
+++ usb-3.4/drivers/usb/host/ehci-sched.c
@@ -481,7 +481,6 @@ static int tt_no_collision (
static int enable_periodic (struct ehci_hcd *ehci)
{
- u32 cmd;
int status;
if (ehci->periodic_sched++)
@@ -497,8 +496,8 @@ static int enable_periodic (struct ehci_
return status;
}
- cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE;
- ehci_writel(ehci, cmd, &ehci->regs->command);
+ ehci->command |= CMD_PSE;
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
/* posted write ... PSS happens later */
/* make sure ehci_work scans these */
@@ -511,7 +510,6 @@ static int enable_periodic (struct ehci_
static int disable_periodic (struct ehci_hcd *ehci)
{
- u32 cmd;
int status;
if (--ehci->periodic_sched)
@@ -537,8 +535,8 @@ static int disable_periodic (struct ehci
return status;
}
- cmd = ehci_readl(ehci, &ehci->regs->command) & ~CMD_PSE;
- ehci_writel(ehci, cmd, &ehci->regs->command);
+ ehci->command &= ~CMD_PSE;
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
/* posted write ... */
free_cached_lists(ehci);
--
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