On Saturday 05 May 2007, Oliver Neukum wrote:
>Am Samstag, 5. Mai 2007 20:08 schrieb Antonino Ingargiola:
>> Now I don't want to abuse your kindness, but I (personally) would be
>> *really* interested in a similar fix for the FTDI usb-serial driver,
>> because many measurements I do use an FTDI device.
>
>Does this work?
>
> Regards
> Oliver
>----
>
>--- a/drivers/usb/serial/ftdi_sio.c 2007-05-05 20:21:41.000000000 +0200
>+++ b/drivers/usb/serial/ftdi_sio.c 2007-05-05 20:27:09.000000000 +0200
>@@ -1749,10 +1749,6 @@ static void ftdi_process_read (struct wo
> length = 0;
> }
>
>- if (priv->rx_flags & THROTTLED) {
>- dbg("%s - throttled", __FUNCTION__);
>- break;
>- }
> if (tty_buffer_request_room(tty, length) < length) {
> /* break out & wait for throttling/unthrottling to happen */
> dbg("%s - receive room low", __FUNCTION__);
>@@ -1825,16 +1821,6 @@ static void ftdi_process_read (struct wo
> dbg("%s - incomplete, %d bytes processed, %d remain",
> __FUNCTION__, packet_offset,
> urb->actual_length - packet_offset);
>- /* check if we were throttled while processing */
>- spin_lock_irqsave(&priv->rx_lock, flags);
>- if (priv->rx_flags & THROTTLED) {
>- priv->rx_flags |= ACTUALLY_THROTTLED;
>- spin_unlock_irqrestore(&priv->rx_lock, flags);
>- dbg("%s - deferring remainder until unthrottled",
>- __FUNCTION__);
>- return;
>- }
>- spin_unlock_irqrestore(&priv->rx_lock, flags);
> /* if the port is closed stop trying to read */
> if (port->open_count > 0){
> /* delay processing of remainder */
>@@ -1856,9 +1842,15 @@ static void ftdi_process_read (struct wo
> port->read_urb->transfer_buffer,
> port->read_urb->transfer_buffer_length, ftdi_read_bulk_callback, port);
>
>- result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
>- if (result)
>- err("%s - failed resubmitting read urb, error %d", __FUNCTION__,
> result); + spin_lock_irqsave(&priv->rx_lock, flags);
>+ if (priv->rx_flags & THROTTLED) {
>+ priv->rx_flags |= ACTUALLY_THROTTLED;
>+ } else {
>+ result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
>+ if (result)
>+ err("%s - failed resubmitting read urb, error %d", __FUNCTION__,
> result); + }
>+ spin_unlock_irqrestore(&priv->rx_lock, flags);
> }
>
> return;
>-
Oliver:
Sort of late, but,
I have a couple of kernels building with this patch applied, one with the
sd-0.48 patch where FTDI stuff is a 40+% cpu hog and can't be used, and one
with the cfs-v10 patch where it can be co-erced into working if I screw with
it enough.
I have also been using another serial patch that for unk reasons, also helps
the usb-serial case here, but vger won't let me repost that without stripping
off the headers. That patch has some resemblance to
this:8250-clear-on-read-bits-LSR-MSR where I usually replace spaces with
dashes so I don't have to use "to surround the name" in my scripts.
So these test kernels will have both patches.
I'll let you know how they work later this morning.
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Oh my GOD -- the SUN just fell into YANKEE STADIUM!!
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