[PATCH] USB: Emagic USB firmware loading fixes

It's become apparent as machines get faster that the emagic kernel firmware
loaders (based on the ezusb loader) have a reset race.  a 400MHz TiBook
never tripped it, but a 2GHz Pentium M seems to hit it about 30% of the
time.  The bug is seen as a hung USB box and the kernel error:

drivers/usb/misc/emi62.c: emi62_load_firmware - error loading firmware:
error = -110

The patch below inserts a delay after deasserting reset to allow the box to
settle before a new command is issued.  This affects only device startup.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/usb/misc/emi62.c b/drivers/usb/misc/emi62.c
index 52fea2e08db8..fe351371f274 100644
--- a/drivers/usb/misc/emi62.c
+++ b/drivers/usb/misc/emi62.c
@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/usb.h>
+#include <linux/delay.h>
 
 #define MAX_INTEL_HEX_RECORD_LENGTH 16
 typedef struct _INTEL_HEX_RECORD
@@ -123,6 +124,7 @@ static int emi62_load_firmware (struct usb_device *dev)
 
         /* De-assert reset (let the CPU run) */
         err = emi62_set_reset(dev,0);
+        msleep(250);    /* let device settle */
 
         /* 2. We upload the FPGA firmware into the EMI
          * Note: collect up to 1023 (yes!) bytes and send them with
@@ -166,6 +168,7 @@ static int emi62_load_firmware (struct usb_device *dev)
                 err("%s - error loading firmware: error = %d", __FUNCTION__, err);
                 goto wraperr;
         }
+        msleep(250);    /* let device settle */
 
         /* 4. We put the part of the firmware that lies in the external RAM into the EZ-USB */
 
@@ -228,6 +231,7 @@ static int emi62_load_firmware (struct usb_device *dev)
                 err("%s - error loading firmware: error = %d", __FUNCTION__, err);
                 goto wraperr;
         }
+        msleep(250);    /* let device settle */
 
         kfree(buf);