| Message ID | 1357595714-13698-2-git-send-email-mikedunn@newsguy.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/07/13 23:55, Mike Dunn wrote: > 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 <mikedunn@newsguy.com> Acked-by: Igor Grinberg <grinberg@compulab.co.il> > --- > sound/arm/pxa2xx-ac97-lib.c | 8 ++++++-- > 1 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c > index 6fc0ae9..1ecd0a66 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 >
diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c index 6fc0ae9..1ecd0a66 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
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 <mikedunn@newsguy.com> --- sound/arm/pxa2xx-ac97-lib.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)