[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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/misc/emi26.c

@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/usb.h>
+#include <linux/delay.h>
 
 #define MAX_INTEL_HEX_RECORD_LENGTH 16
 typedef struct _INTEL_HEX_RECORD
@@ -114,6 +115,7 @@ static int emi26_load_firmware (struct usb_device *dev)
 
 	/* De-assert reset (let the CPU run) */
 	err = emi26_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
@@ -150,6 +152,7 @@ static int emi26_load_firmware (struct usb_device *dev)
 			goto wraperr;
 		}
 	}
+	msleep(250);	/* let device settle */
 
 	/* De-assert reset (let the CPU run) */
 	err = emi26_set_reset(dev,0);
@@ -192,6 +195,7 @@ static int emi26_load_firmware (struct usb_device *dev)
 		err("%s - error loading firmware: error = %d", __FUNCTION__, err);
 		goto wraperr;
 	}
+	msleep(250);	/* let device settle */
 
 	/* return 1 to fail the driver inialization
 	 * and give real driver change to load */

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);