Hello,
> I encourage you to go ahead and change code sequences like that one also,
> whenever it's safe to do so.
Ok I'll make another approach when those 33 get merged.
The thing is there are simple code sequences that can be fixed:
if (urb) {
usb_kill_urb(urb);
usb_free_urb(urb);
}
then there are more complex ones like this one:
if (urb) {
dbg("we hit this and blah blah ...");
usb_kill_urb(urb);
usb_free_urb(urb);
urb = NULL;
}
which probably should not be touched as it would cause them to emit those
debug messages all the time the code sequence is executed even if urb == NULL.
The other story are sequences executed in a loop:
for (i = 0; ...; i++) {
if (urb) {
usb_kill_urb(urb);
usb_free_urb(urb);
urb = NULL;
}
}
where removing 'if' causes calling all three lines each time even if urb == NULL
thus probably resulting in some slowdown(?). Ayway I don't think the slowdown is
important here and those 'if's can be safely removed.
The next thing found when digging the code is this common sequence:
if (mc->data)
usb_buffer_free(dev, URB_INT_SIZE, mc->data, mc->data_dma);
which is also redundant. This is from 2.6.19-rc5-mm2:
void usb_buffer_free (struct usb_device *dev, size_t size, void *addr,
dma_addr_t dma)
{
if (!dev || !dev->bus)
return;
if (!addr)
return;
hcd_buffer_free (dev->bus, size, addr, dma);
}
The only thing is that 'addr' is not checked at the beggining so
usb_buffer_free()
might be rewritten to:
void usb_buffer_free (struct usb_device *dev, size_t size, void *addr,
dma_addr_t dma)
{
if (!addr || !dev || !dev->bus)
return;
hcd_buffer_free (dev->bus, size, addr, dma);
}
what makes sense to me because the 'addr' pointer is what this function is
about so it
should be checked first.
I could do that in one series of patches. It is simple enough not to break
things and
hopefuly remove lots of redundant code. What do you thik of these (proposed)
changes?
--
Regards,
Mariusz Kozlowski
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