Hi Takashi, > -----Original Message----- > From: Takashi Iwai [mailto:[email protected]] > Sent: Thursday, August 06, 2015 5:21 PM > To: Yang, Libin > Cc: [email protected]; [email protected]; Lin, > Mengdong > Subject: Re: [alsa-devel] [PATCH 2/4] drm/i915: implement set_ncts > callback > > On Thu, 06 Aug 2015 08:52:55 +0200, > [email protected] wrote: > > > > From: Libin Yang <[email protected]> > > > > Display audio may not work at some frequencies > > with the HW provided N/CTS. > > > > This patch sets the proper N value for the > > given audio sample rate at the impacted frequencies. > > At other frequencies, it will use the N/CTS value > > which HW provides. > > > > Signed-off-by: Libin Yang <[email protected]> > > --- > > drivers/gpu/drm/i915/i915_reg.h | 2 + > > drivers/gpu/drm/i915/intel_audio.c | 93 > ++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 95 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h > b/drivers/gpu/drm/i915/i915_reg.h > > index 3a77678..0b1cd72 100644 > > --- a/drivers/gpu/drm/i915/i915_reg.h > > +++ b/drivers/gpu/drm/i915/i915_reg.h > > @@ -7010,6 +7010,8 @@ enum skl_disp_power_wells { > > _HSW_AUD_MISC_CTRL_A, \ > > _HSW_AUD_MISC_CTRL_B) > > > > +#define HSW_AUD_PIPE_CONN_SEL_CTRL 0x650ac > > + > > #define _HSW_AUD_DIP_ELD_CTRL_ST_A 0x650b4 > > #define _HSW_AUD_DIP_ELD_CTRL_ST_B 0x651b4 > > #define HSW_AUD_DIP_ELD_CTRL(pipe) _PIPE(pipe, \ > > diff --git a/drivers/gpu/drm/i915/intel_audio.c > b/drivers/gpu/drm/i915/intel_audio.c > > index dc32cf4..f1148cd 100644 > > --- a/drivers/gpu/drm/i915/intel_audio.c > > +++ b/drivers/gpu/drm/i915/intel_audio.c > > @@ -68,6 +68,28 @@ static const struct { > > { 148500, AUD_CONFIG_PIXEL_CLOCK_HDMI_148500 }, > > }; > > > > +static const struct { > > + int sample_rate; > > + int clock; > > + int n; > > + int cts; > > +} aud_ncts[] = { > > + { 44100, DIV_ROUND_UP(297000 * 1000, 1001), 4459, 234375 }, > > + { 44100, 297000, 4704, 247500 }, > > As these two clock values are referred repeatedly in other places, > it'd be better to define constants.
Do you mean use Macro such as: #define 297MHZ 297000 #define 296MHZ DIV_ROUND_UP(297000 * 1000, 1001) > > > Takashi _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
