From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Dunn Subject: Re: [PATCH] ALSA: pxa2xx: fix ac97 cold reset for pxa27x Date: Sun, 30 Dec 2012 17:14:48 -0800 Message-ID: <50E0E708.2090005@newsguy.com> References: <1356707815-3235-1-git-send-email-mikedunn@newsguy.com> <87wqw2rq92.fsf@free.fr> <50DE54D2.9040608@newsguy.com> <87han3smyc.fsf@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.newsguy.com (smtp.newsguy.com [74.209.136.69]) by alsa0.perex.cz (Postfix) with ESMTP id 3E4712616C8 for ; Mon, 31 Dec 2012 02:14:25 +0100 (CET) In-Reply-To: <87han3smyc.fsf@free.fr> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Robert Jarzmik Cc: Marek Vasut , alsa-devel@alsa-project.org, Mark Brown , Eric Miao List-Id: alsa-devel@alsa-project.org On 12/30/2012 05:12 AM, Robert Jarzmik wrote: > Mike Dunn writes: > >> On 12/28/2012 10:22 AM, Robert Jarzmik wrote: >>> Mike Dunn writes: >>> >>>> Currently, ac97 reset is broken on PXA27x. Through trial-and-error (the pxa270 >>>> developer's manual is mostly incoherent on the topic of ac97 reset), I fixed it >>>> by setting the WARM_RST bit in the GCR register at the end of the cold reset, >>>> and then skipping the warm reset if the link is already up and running. >>>> >>>> It appears that setting the WARM_RST bit is a necessary final step during cold >>>> reset. I think that the PXA25x and PXA3xx may currently be working correctly >>>> because WARM_RST is set within the warm reset routine, and the codec drivers >>>> always follow a cold reset with a warm reset during their initialization. so >>>> this combination effectively completes a cold reset. This doesn't work on the >>>> PXA27x because its warm reset routine contains additional code for working >>>> around a hardware bug in the warm reset sequence, which causes the reset >>>> sequence to fail. I only have a PXA27x platform for testing, so this patch only >>>> affects the PXA27x. >>> If you've tested that and if it work, that's great news. I'll test it also to >>> crosscheck. >> >> >> Thanks. I'd really appreciate that. Yes, it works for me. > > Ok, I tested it, through a suspend/resume cycle with a music played, and it > works, and the patch looks correct to me. So : > > Tested-by: Robert Jarzmik > Reviewed-by: Robert Jarzmik Great! Many thanks Robert! Mike