Messages in this thread | | | Subject | Re: [PATCH 1/1] TX throttling bug-fixing patch of AX88179_178A | From | Ben Hutchings <> | Date | Thu, 25 Jul 2013 14:34:03 +0100 |
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On Thu, 2013-07-25 at 13:25 +0800, Ming Lei wrote: > On Thu, Jul 25, 2013 at 1:10 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > > On Thu, 2013-07-25 at 10:28 +0800, Ming Lei wrote: > > > >> > >> It depends if size of sg buffer(except for last one) in the sg list can be > >> divided by usb endpoint's max packet size(512 or 1024), at least there > >> is the constraint: > >> > >> http://git.kernel.org/cgit/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=10e232c597ac757e7f8600649f7e872e86de190f > >> > >> I am wondering if network stack can meet that. If not, it might be a > >> bit difficult > >> because lots of USB host controller don't support that, and driver may have > >> to support SG and non-SG at the same time for working well on all HCs. > > > > I do not see the problem. > > > > If one skb has 2 fragments of 32KB, couldn't they be split into 64 1K > > segments by the device driver ? > > OK, if length of fragments of all SKBs from network stack can always guarantee > to be divided by 1024, that is fine, seems I worry about too much, :-)
Not that I have any experience with USB drivers, but perhaps usb_sg_init()?
Ben.
-- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.
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