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-hcd.c b/drivers/usb/host/ehci-hcd.c
index a87c057..de1e689 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -226,8 +226,13 @@
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 @@
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 @@
#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,