UHCI: workaround for Asus motherboard

This patch (as798) adds a workaround to uhci-hcd.  At least one Asus
motherboard is wired in such a way that any device attached to a
suspended UHCI controller will prevent the system from entering
suspend-to-RAM by immediately waking it up.  The only way around the
problem is to turn the controller off instead of suspending it.

This fixes Bugzilla #6193.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 45ee6920a850b6369ec7ecd883d2278ecc815830..226bf3de8edd5ce092c551f0a90daa96ba2fc9e4 100644 (file)
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -40,6 +40,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/usb.h>
 #include <linux/bitops.h>
+#include <linux/dmi.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -196,12 +197,42 @@ static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
        return 0;
 }
 
+static int remote_wakeup_is_broken(struct uhci_hcd *uhci)
+{
+       static struct dmi_system_id broken_wakeup_table[] = {
+               {
+                       .ident = "Asus A7V8X",
+                       .matches = {
+                               DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK"),
+                               DMI_MATCH(DMI_BOARD_NAME, "A7V8X"),
+                               DMI_MATCH(DMI_BOARD_VERSION, "REV 1.xx"),
+                       }
+               },
+               { }
+       };
+       int port;
+
+       /* One of Asus's motherboards has a bug which causes it to
+        * wake up immediately from suspend-to-RAM if any of the ports
+        * are connected.  In such cases we will not set EGSM.
+        */
+       if (dmi_check_system(broken_wakeup_table)) {
+               for (port = 0; port < uhci->rh_numports; ++port) {
+                       if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
+                                       USBPORTSC_CCS)
+                               return 1;
+               }
+       }
+
+       return 0;
+}
+
 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
 __releases(uhci->lock)
 __acquires(uhci->lock)
 {
        int auto_stop;
-       int int_enable;
+       int int_enable, egsm_enable;
 
        auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
        dev_dbg(&uhci_to_hcd(uhci)->self.root_hub->dev,
@@ -217,15 +248,18 @@ __acquires(uhci->lock)
        }
 
        /* Enable resume-detect interrupts if they work.
-        * Then enter Global Suspend mode, still configured.
+        * Then enter Global Suspend mode if _it_ works, still configured.
         */
+       egsm_enable = USBCMD_EGSM;
        uhci->working_RD = 1;
        int_enable = USBINTR_RESUME;
-       if (resume_detect_interrupts_are_broken(uhci)) {
+       if (remote_wakeup_is_broken(uhci))
+               egsm_enable = 0;
+       if (resume_detect_interrupts_are_broken(uhci) || !egsm_enable)
                uhci->working_RD = int_enable = 0;
-       }
+
        outw(int_enable, uhci->io_addr + USBINTR);
-       outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
+       outw(egsm_enable | USBCMD_CF, uhci->io_addr + USBCMD);
        mb();
        udelay(5);