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>

1 files changed, 39 insertions, 5 deletions

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 45ee6920a850..226bf3de8edd 100644
--- 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);