Re: [Intel-gfx] [PATCH] drm/i915: set AUD_CONFIG N_value_index forDisplayPort

From: Wu Fengguang
Date: Mon Jan 16 2012 - 18:08:10 EST


On Mon, Jan 16, 2012 at 12:44:43PM -0800, Keith Packard wrote:
> On Mon, 16 Jan 2012 21:26:18 +0100, Daniel Vetter <daniel@xxxxxxxx> wrote:
>
> > Keith, does this address your concern and this patch is r-b: Keith or do
> > we want an
> >
> > } else {
> > I915_WRITE(aud_config, 0);
> > }
> >
> > for paranoia?
>
> I think we want this added, just to be sure we set the configuration
> correctly in all cases; it's easy to imagine moving from DP to HDMI and
> leaving this bit set.

Ah good point! Here is the updated patch.

---
Subject: drm/i915: set AUD_CONFIG N_value_index for DisplayPort
Date: Fri Jan 06 14:41:31 CST 2012

It should be programmed to "0" for HDMI or "1" for DisplayPort.

This enables DisplayPort audio for

- HP EliteBook 8460p
(whose BIOS does not set the N_value_index bit for us)

- DisplayPort monitor hot plugged after boot
(otherwise most BIOS will fill the N_value_index bit for us)

Tested-by: Robert Lemaire <rlemaire@xxxxxxxx>
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_reg.h | 12 ++++++++++++
drivers/gpu/drm/i915/intel_display.c | 8 +++++++-
2 files changed, 19 insertions(+), 1 deletion(-)

--- linux.orig/drivers/gpu/drm/i915/i915_reg.h 2012-01-07 23:11:10.000000000 +0800
+++ linux/drivers/gpu/drm/i915/i915_reg.h 2012-01-10 13:20:17.000000000 +0800
@@ -3582,4 +3582,16 @@
#define CPT_AUD_CNTL_ST_A 0xE50B4
#define CPT_AUD_CNTRL_ST2 0xE50C0

+#define IBX_AUD_CONFIG_A 0xe2000
+#define CPT_AUD_CONFIG_A 0xe5000
+#define AUD_CONFIG_N_VALUE_INDEX (1 << 29)
+#define AUD_CONFIG_N_PROG_ENABLE (1 << 28)
+#define AUD_CONFIG_UPPER_N_SHIFT 20
+#define AUD_CONFIG_UPPER_N_VALUE (0xff << 20)
+#define AUD_CONFIG_LOWER_N_SHIFT 4
+#define AUD_CONFIG_LOWER_N_VALUE (0xfff << 4)
+#define AUD_CONFIG_PIXEL_CLOCK_HDMI_SHIFT 16
+#define AUD_CONFIG_PIXEL_CLOCK_HDMI (0xf << 16)
+#define AUD_CONFIG_DISABLE_NCTS (1 << 3)
+
#endif /* _I915_REG_H_ */
--- linux.orig/drivers/gpu/drm/i915/intel_display.c 2012-01-07 23:11:10.000000000 +0800
+++ linux/drivers/gpu/drm/i915/intel_display.c 2012-01-17 07:06:29.000000000 +0800
@@ -5908,15 +5908,18 @@ static void ironlake_write_eld(struct dr
uint32_t i;
int len;
int hdmiw_hdmiedid;
+ int aud_config;
int aud_cntl_st;
int aud_cntrl_st2;

if (HAS_PCH_IBX(connector->dev)) {
hdmiw_hdmiedid = IBX_HDMIW_HDMIEDID_A;
+ aud_config = IBX_AUD_CONFIG_A;
aud_cntl_st = IBX_AUD_CNTL_ST_A;
aud_cntrl_st2 = IBX_AUD_CNTL_ST2;
} else {
hdmiw_hdmiedid = CPT_HDMIW_HDMIEDID_A;
+ aud_config = CPT_AUD_CONFIG_A;
aud_cntl_st = CPT_AUD_CNTL_ST_A;
aud_cntrl_st2 = CPT_AUD_CNTRL_ST2;
}
@@ -5924,6 +5927,7 @@ static void ironlake_write_eld(struct dr
i = to_intel_crtc(crtc)->pipe;
hdmiw_hdmiedid += i * 0x100;
aud_cntl_st += i * 0x100;
+ aud_config += i * 0x100;

DRM_DEBUG_DRIVER("ELD on pipe %c\n", pipe_name(i));

@@ -5943,7 +5947,9 @@ static void ironlake_write_eld(struct dr
if (intel_pipe_has_type(crtc, INTEL_OUTPUT_DISPLAYPORT)) {
DRM_DEBUG_DRIVER("ELD: DisplayPort detected\n");
eld[5] |= (1 << 2); /* Conn_Type, 0x1 = DisplayPort */
- }
+ I915_WRITE(aud_config, AUD_CONFIG_N_VALUE_INDEX); /* 0x1 = DP */
+ } else
+ I915_WRITE(aud_config, 0);

if (intel_eld_uptodate(connector,
aud_cntrl_st2, eldv,
--
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