EHCI: maintain the ehci->command value properly
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@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 36ca507..13f4f98 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -981,14 +981,12 @@
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 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 @@
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 @@
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);
}