Am 29.10.2013 18:12, schrieb Frank Schäfer: > Am 29.10.2013 10:07, schrieb Mika Westerberg: >> On Mon, Oct 28, 2013 at 07:50:44PM +0100, Frank Schäfer wrote: >>> Mika Westerberg has reported that the fixed+improved divisor based baud rate >>> encoding method doesn't work anymore with his HXD device. >>> So until we've found out what's going on, reintroduce the old encoding algorithm >>> and use it for this and all newer chips for baud rates > 115200 baud. >>> Also switch back to the direct encoding method for baud rates <= 115200, because >>> it's unclear if the old divisor based encoding algorithm works for them. >>> >>> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> >>> Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx> >> Tried this and with 115200 it works and fixes the problem. However, with >> speeds like 230400 and 460800 it still corrupts data. > Well, with this patch we go back to what we did since kernel 3.1 (since > commit 8d48fdf689fe "USB: PL2303: correctly handle baudrates above > 115200"), so you should face the same problems with these kernels, too. I've double checked that. With this patch applied to 3.12-rc the baud rate encoding is exactly the same as in 3.11 (for HXD chips). Are you sure your test setup is reliable / comparable ? Could you please re-check your results ? Regards, Frank > > Please note that there are serious doubts with regards to the baud rate > precision of this algorithm and if it has really ever been working with > all chips. > The commit description doesn't say where it comes from (likey based on > reverse-enginnering) and which chips it tries to fix. :( We've contacted > the author, but got no reply. > With HX chips, it only worked "more or less" for baud rates ~115200 to > ~500000 and but the actual baud rate always differed a little. > With commit 57ce61aad748 we fixed/improved this algorithm, but > apparently this doesn't work for HXD chips (which is a bit surprising). > > I hope I'll get one of these devices at the end of this week. > >> I also got few whitespace warnings when applied this using 'git am'. > Ick, thanks. Will send a fixed version. > > Regards, > Frank > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
