Date: Tue, 27 Mar 2007 18:54:38 +0200 From: Hans Petter Selasky <hselasky@c2i.net> To: freebsd-usb@freebsd.org Cc: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Subject: Re: fix uhci suspend Message-ID: <200703271854.38239.hselasky@c2i.net> In-Reply-To: <20070327095301.GA1439@shorty.sorbonet.org> References: <20070327095301.GA1439@shorty.sorbonet.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tuesday 27 March 2007 11:53, Andrea Bittau wrote:
> To suspend, you need to:
> 1) stop the controller
> 2) set the global suspend bit
>
> The current code does:
> cmd = UREAD2(sc, UHCI_CMD);
> ...
> uhci_run(sc, 0); /* stop the controller */
> ...
> UHCICMD(sc, cmd | UHCI_CMD_EGSM); /* enter global suspend */
>
> The problem is that cmd is not re-read after stopping the controller, so
> cmd will still have the run bit set to 1 instead of 0. Thus, when entering
> suspend, the controller's run bit will be put back to 1 and the controller
> will freak out. The attached patch fixes this. I don't know if the resume
> branch of the code suffers from this problem too---I'm working on suspend
> for now. With my patch, I can get ICH7 82801G to suspend, otherwise,
> suspend would just hang the box.
That is correctly noticed.
In my new USB stack I simply do:
/* enter global suspend */
UHCICMD(sc, UHCI_CMD_EGSM);
Clearing all other bits.
Could you have tried the SVN version of the new USB stack and see if
suspend/resume works there?
http://www.turbocat.net/~hselasky/usb4bsd
--HPS
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200703271854.38239.hselasky>