From patchwork Wed Jan 23 04:42:50 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3.5.y.z, extended, stable] Patch "ALSA: pxa27x: fix ac97 cold reset" has been added to staging queue Date: Tue, 22 Jan 2013 18:42:50 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 214754 Message-Id: <1358916170-22980-1-git-send-email-herton.krzesinski@canonical.com> To: Mike Dunn Cc: kernel-team@lists.ubuntu.com, Mark Brown , Igor Grinberg This is a note to let you know that I have just added a patch titled ALSA: pxa27x: fix ac97 cold reset to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ >From c984707f6799fad8e61d12970f18458a3af154b8 Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Mon, 7 Jan 2013 13:55:12 -0800 Subject: [PATCH] ALSA: pxa27x: fix ac97 cold reset commit 41b645c8624df6ace020a8863ad1449d69140f7d upstream. Cold reset on the pxa27x currently fails and pxa2xx_ac97_try_cold_reset: cold reset timeout (GSR=0x44) appears in the kernel log. Through trial-and-error (the pxa270 developer's manual is mostly incoherent on the topic of ac97 reset), I got cold reset to complete by setting the WARM_RST bit in the GCR register (and later noticed that pxa3xx does this for cold reset as well). Also, a timeout loop is needed to wait for the reset to complete. Tested on a palm treo 680 machine. Signed-off-by: Mike Dunn Acked-by: Igor Grinberg Signed-off-by: Mark Brown Signed-off-by: Herton Ronaldo Krzesinski --- sound/arm/pxa2xx-ac97-lib.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) -- 1.7.9.5 diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c index 48d7c0a..8cfb2c0 100644 --- a/sound/arm/pxa2xx-ac97-lib.c +++ b/sound/arm/pxa2xx-ac97-lib.c @@ -148,6 +148,8 @@ static inline void pxa_ac97_warm_pxa27x(void) static inline void pxa_ac97_cold_pxa27x(void) { + unsigned int timeout; + GCR &= GCR_COLD_RST; /* clear everything but nCRST */ GCR &= ~GCR_COLD_RST; /* then assert nCRST */ @@ -157,8 +159,10 @@ static inline void pxa_ac97_cold_pxa27x(void) clk_enable(ac97conf_clk); udelay(5); clk_disable(ac97conf_clk); - GCR = GCR_COLD_RST; - udelay(50); + GCR = GCR_COLD_RST | GCR_WARM_RST; + timeout = 100; /* wait for the codec-ready bit to be set */ + while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--) + mdelay(1); } #endif