[PATCH 17/29] USB: remove short initial timeout for device descriptor fetch
Greg Kroah-Hartman <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
From: Alan Stern <[email protected]> This patch (as905) removes a micro-optimization from the hub port initialization code. Previously we had been using a short timeout on the first attempt the read the device descriptor; now we will use the standard timeout length. It's not clear that the short timeout ever provided any benefit. And now we know of one case where it actually hurts: The device can't meet the short timeout and then it gets terminally confused. This fixes Bugzilla #8444. Signed-off-by: Alan Stern <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/usb/core/hub.c | 13 ++++--------- 1 files changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index f6b74a6..6a6e4f8 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2201,14 +2201,9 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1, continue; } - /* Use a short timeout the first time through, - * so that recalcitrant full-speed devices with - * 8- or 16-byte ep0-maxpackets won't slow things - * down tremendously by NAKing the unexpectedly - * early status stage. Also, retry on all errors; - * some devices are flakey. - * 255 is for WUSB devices, we actually need to use 512. - * WUSB1.0[4.8.1]. + /* Retry on all errors; some devices are flakey. + * 255 is for WUSB devices, we actually need to use + * 512 (WUSB1.0[4.8.1]). */ for (j = 0; j < 3; ++j) { buf->bMaxPacketSize0 = 0; @@ -2216,7 +2211,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1, USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, USB_DT_DEVICE << 8, 0, buf, GET_DESCRIPTOR_BUFSIZE, - (i ? USB_CTRL_GET_TIMEOUT : 1000)); + USB_CTRL_GET_TIMEOUT); switch (buf->bMaxPacketSize0) { case 8: case 16: case 32: case 64: case 255: if (buf->bDescriptorType == -- 1.5.1.4 ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel