On Wed, Jan 26, 2011 at 2:07 PM, Dan Carpenter <error27@xxxxxxxxx> wrote: > You didn't introduce it but do you know what the code is trying to do > here? > > Â Â Â Âbyte_length = word_length * 4; > > Â Â Â Âif (byte_length % 4) > Â Â Â Â Â Â Â Âaligncnt = 4 - (byte_length % 4); > Â Â Â Âelse > Â Â Â Â Â Â Â Âaligncnt = 0; > Â Â Â Âbyte_length += aligncnt; > > Â Â Â Âif (byte_length && ((byte_length % 64) == 0)) > Â Â Â Â Â Â Â Âbyte_length += 4; > > Â Â Â Âif (byte_length < 64) > Â Â Â Â Â Â Â Âbyte_length = 68; > > > Apparently the stuff has to be aligned to 4 bytes, but it can't be > aligned at 64 bytes and it can't be less than 68 bytes long. ÂThe > part that especially confuses me is why it can't be aligned at 64 bytes. Yes this code seems little bit confusing but basically this routine send data to device when firmware code is downloaded. Length which should be send is asked by device itself (word_length) so maybe it should be somehow aligned in some cases (don't know details). Just to get some idea about length I add some printk(before 4*word_length and after byte_length is counted before sending to usb): Jan 26 14:22:24 linux kernel: [29632.843980] write_blk_fifo: word_length:4 Jan 26 14:22:24 linux kernel: [29632.843984] write_blk_fifo: byte_length:68 Jan 26 14:22:24 linux kernel: [29632.859982] write_blk_fifo: word_length:506 Jan 26 14:22:24 linux kernel: [29632.859986] write_blk_fifo: byte_length:2024 Jan 26 14:22:24 linux kernel: [29632.874984] write_blk_fifo: word_length:505 Jan 26 14:22:24 linux kernel: [29632.874988] write_blk_fifo: byte_length:2020 Jan 26 14:22:24 linux kernel: [29632.890046] write_blk_fifo: word_length:4 Jan 26 14:22:24 linux kernel: [29632.890051] write_blk_fifo: byte_length:68 > > regards, > dan carpenter > thanks, marek -- as simple and primitive as possible ------------------------------------------------- Marek Belisko - OPEN-NANDRA Freelance Developer Ruska Nova Ves 219 | Presov, 08005 Slovak Republic Tel: +421 915 052 184 skype: marekwhite icq: 290551086 web: http://open-nandra.com _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
