Re: [PATCH 2/3] drm/i915: Initialize CHV digital lock detect threshold

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 3/3/2015 9:08 PM, Ville Syrjälä wrote:
On Tue, Mar 03, 2015 at 08:43:12PM +0530, Vijay Purushothaman wrote:
Initialize lock detect threshold and select coarse threshold for the
case where M2 fraction division is disabled.

v2: Split the changes into multiple smaller patches based on review by
Ville

v3: Addressed rest of the review comments. Clear out the old bits before
we modify those bits as part of RMW

Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman@xxxxxxxxxxxxxxx>
---
  drivers/gpu/drm/i915/i915_reg.h      |    1 +
  drivers/gpu/drm/i915/intel_display.c |   13 +++++++++++++
  2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8200e98..1a0f94e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1046,6 +1046,7 @@ enum skl_disp_power_wells {
  #define _CHV_PLL_DW9_CH0		0x8024
  #define _CHV_PLL_DW9_CH1		0x81A4
  #define  DPIO_CHV_INT_LOCK_THRESHOLD_SHIFT		1 /* 3 bits */
+#define  DPIO_CHV_INT_LOCK_THRESHOLD_MASK		(7 << 1)
  #define  DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE	1 /* 1: coarse & 0 : fine  */
  #define CHV_PLL_DW9(ch) _PIPE(ch, _CHV_PLL_DW9_CH0, _CHV_PLL_DW9_CH1)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 15904a8..a6b5786 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6176,11 +6176,24 @@ static void chv_prepare_pll(struct intel_crtc *crtc,
  		dpio_val |= (2 << DPIO_CHV_FEEDFWD_GAIN_SHIFT);
  		vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW3(port), dpio_val);
+ /* Program digital lock detect threshold */
+		dpio_val = vlv_dpio_read(dev_priv, pipe, CHV_PLL_DW9(port));
+		dpio_val &= ~DPIO_CHV_INT_LOCK_THRESHOLD_MASK;
+		dpio_val |= (0x5 << DPIO_CHV_INT_LOCK_THRESHOLD_SHIFT);
Missing
  dpio_val &= ~DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE;
here.

So I think to avoid such mistakes it's best to rewrite this too as:

val = read(PLL_DW9)
val &= ~(DPIO_CHV_INT_LOCK_THRESHOLD_MASK | DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE);
val |= 0x5 << DPIO_CHV_INT_LOCK_THRESHOLD_SHIFT)
if (!bestm2_frac)
	val |= DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE;
write(PLL_DW9, val);

I will send v4 with this change and add your signed-off-by tag.

Thanks,
Vijay

+		vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW9(port), dpio_val);
+
  	} else {
  		/* M2 fraction division disable */
  		dpio_val = vlv_dpio_read(dev_priv, pipe, CHV_PLL_DW3(port));
  		dpio_val &= ~DPIO_CHV_FRAC_DIV_EN;
  		vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW3(port), dpio_val);
+
+		/* Program digital lock detect threshold */
+		dpio_val = vlv_dpio_read(dev_priv, pipe, CHV_PLL_DW9(port));
+		dpio_val &= ~DPIO_CHV_INT_LOCK_THRESHOLD_MASK;
+		dpio_val |= (0x5 << DPIO_CHV_INT_LOCK_THRESHOLD_SHIFT);
+		dpio_val |= DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE;
+		vlv_dpio_write(dev_priv, pipe, CHV_PLL_DW9(port), dpio_val);
  	}
/* Loop filter */
--
1.7.9.5

_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx





[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux