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EHCI: maintain the ehci->command value properly

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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>
This commit is contained in:
Alan Stern
2012-04-23 13:54:36 -04:00
committed by Greg Kroah-Hartman
parent 09091a4d5f
commit 3d9545cc37
5 changed files with 23 additions and 27 deletions
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6
drivers/usb/host/ehci-dbg.c
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@@ -1025,10 +1025,8 @@ static ssize_t debug_lpm_write(struct file *file, const char __user *user_buf,
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;