This is the mail archive of the
ecos-discuss@sources.redhat.com
mailing list for the eCos project.
Splitting USB-Packets
- From: "Fuchs, Torsten" <Torsten dot Fuchs at jenoptik dot com>
- To: <ecos-discuss at sources dot redhat dot com>
- Date: Wed, 13 Apr 2005 16:07:08 +0200
- Subject: [ECOS] Splitting USB-Packets
Hi,
I need to send or receive large amounts of data via USB using the usbs slave. The data sizes can under certain circumstances be larger then the RAM in the system so I have to split the data into blocks. From the hosts point of view there shall be only one big USB-packet.
Receiving is not a problem but transmitting. When sending multiples of the maximum packet size (64 Bytes) the device driver generates a zero length packet to end the data transfer. So the host sees an interrupted packet. I need an option to supress the generation of this zero length packet to continue the transmission with another call of usbs_start_tx. Only the last block should be finished with a zero length packet.
Every modification would not be compatible to the slave package so how can I solve this problem? In my opinion there should be an additional flag to enable/ disable the generation of the last packet by the driver.
Thanks
Torsten
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss