From 4c1bd3d7a7d114dabd58f62f386ac4bfd268be1f Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Mon, 24 Aug 2009 14:44:30 +0100 Subject: USB: make urb scatter-gather support more generic The WHCI HCD will also support urbs with scatter-gather lists. Add a usb_bus field to indicated how many sg list elements are supported by the HCD. Use this to decide whether to pass the scatter-list to the HCD or not. Make the usb-storage driver use this new field. Signed-off-by: David Vrabel Cc: Alan Stern Cc: Sarah Sharp Cc: Matthew Dharm Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/usb/storage/usb.c') diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 01e43a1..1599d86 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -843,6 +843,15 @@ static int usb_stor_scan_thread(void * __us) complete_and_exit(&us->scanning_done, 0); } +static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf) +{ + struct usb_device *usb_dev = interface_to_usbdev(intf); + + if (usb_dev->bus->sg_tablesize) { + return usb_dev->bus->sg_tablesize; + } + return SG_ALL; +} /* First part of general USB mass-storage probing */ int usb_stor_probe1(struct us_data **pus, @@ -871,6 +880,7 @@ int usb_stor_probe1(struct us_data **pus, * Allow 16-byte CDBs and thus > 2TB */ host->max_cmd_len = 16; + host->sg_tablesize = usb_stor_sg_tablesize(intf); *pus = us = host_to_us(host); memset(us, 0, sizeof(struct us_data)); mutex_init(&(us->dev_mutex)); -- cgit v1.1