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-sched.c b/drivers/usb/host/ehci-sched.c
index a60679c..ffe8fc3 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -481,7 +481,6 @@
static int enable_periodic (struct ehci_hcd *ehci)
{
- u32 cmd;
int status;
if (ehci->periodic_sched++)
@@ -497,8 +496,8 @@
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 disable_periodic (struct ehci_hcd *ehci)
{
- u32 cmd;
int status;
if (--ehci->periodic_sched)
@@ -537,8 +535,8 @@
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);