usb-storage: Wait less time for settling when a memory device is connected

[Martin Bammer <mrbm74@gmail.com>]

Hi,

I was wondering why the usb-storage driver waits for my usb-stick and my
sdhc-card 5s before scanning. IMHO this is only needed for HDs. I've
created a patch for the driver which shortens the timeout to 1s when a
memory device is detected.
But I'm not shure if the detection code is right for all devices. This
maybe has to be tested and discussed.
I've tested it with a usb-stick, a sdhc-card and a usb-harddrive.
This patch is created for kernel 2.6.27.18.

Please CC me for answers to this thread.

--- a/drivers/usb/storage/usb.c 2009-03-03 23:33:37.000000000 +0100
+++ b/drivers/usb/storage/usb.c 2009-03-03 23:32:44.000000000 +0100
@@ -913,10 +913,16 @@ static int usb_stor_scan_thread(void * _
 
        set_freezable();
 
+       /* Shorten delay time for memory sticks/cards */
+       if ((1 == us->pusb_dev->descriptor.iManufacturer)
+           && (2 == us->pusb_dev->descriptor.iProduct)
+           && (3 == us->pusb_dev->descriptor.iSerialNumber)
+           && (delay_use > 0)) delay_use = 1;
+
        /* Wait for the timeout to expire or for a disconnect */
        if (delay_use > 0) {
                printk(KERN_DEBUG "usb-storage: waiting for device "
-                               "to settle before scanning\n");
+                               "to settle before scanning for %d
seconds\n", delay_use);
                wait_event_freezable_timeout(us->delay_wait,
                                test_bit(US_FLIDX_DONT_SCAN,
&us->dflags),
                                delay_use * HZ);