On 9/12/2018 12:56 AM, Jani Nikula wrote:
On Fri, 20 Jul 2018, "Chauhan, Madhav" <madhav.chauhan@xxxxxxxxx> wrote:
-----Original Message-----
From: Ville Syrjälä [mailto:ville.syrjala@xxxxxxxxxxxxxxx]
Sent: Thursday, July 19, 2018 9:51 PM
To: Chauhan, Madhav <madhav.chauhan@xxxxxxxxx>
Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Nikula, Jani <jani.nikula@xxxxxxxxx>;
Zanoni, Paulo R <paulo.r.zanoni@xxxxxxxxx>; Vivi, Rodrigo
<rodrigo.vivi@xxxxxxxxx>
Subject: Re: [PATCH v5 09/13] drm/i915/icl: Program
TA_TIMING_PARAM registers
On Tue, Jul 10, 2018 at 03:10:10PM +0530, Madhav Chauhan wrote:
This patch programs D-PHY timing parameters for the bus turn around
flow(in escape clocks) only if dsi link frequency <=800 MHz using
DPHY_TA_TIMING_PARAM and its identical register
DSI_TA_TIMING_PARAM
(inside DSI Controller within the Display Core).
Signed-off-by: Madhav Chauhan <madhav.chauhan@xxxxxxxxx>
---
drivers/gpu/drm/i915/icl_dsi.c | 21 +++++++++++++++++++++
drivers/gpu/drm/i915/intel_dsi.h | 1 +
drivers/gpu/drm/i915/intel_dsi_vbt.c | 1 +
3 files changed, 23 insertions(+)
diff --git a/drivers/gpu/drm/i915/icl_dsi.c
b/drivers/gpu/drm/i915/icl_dsi.c index 832772d..8fd5284 100644
--- a/drivers/gpu/drm/i915/icl_dsi.c
+++ b/drivers/gpu/drm/i915/icl_dsi.c
@@ -302,6 +302,27 @@ static void gen11_dsi_setup_dphy_timings(struct
intel_encoder *encoder)
I915_WRITE(DSI_DATA_TIMING_PARAM(port),
intel_dsi->dphy_data_lane_reg);
}
+
+ /*
+ * If DSI link operating at or below an 800 MHz,
+ * TA_SURE should be override and programmed to
+ * a value '0' inside TA_PARAM_REGISTERS otherwise
+ * leave all fields at HW default values.
+ */
+ if (intel_dsi->bitrate_khz <= KHz(800)) {
The KHz(800) confuses me. My brain thinks this value is 800 kHz when it's
not. So I'd write it without the KHz() macro.
Ok. Initially I wrote without using KHz macro, but got comment to use KHz macro :)
Did I? Oh well. Go with 800000.
Ok :)
Please don't add additional state with intel_dsi->bitrate_khz when you
can calculate the bitrate at any time. Add a function to do it if you
like, and use it in both places.
Ok. But we will reusing this bitrate(same value) in multiple place.
Shouldn't
we cache it rather than calculating everytime??
Regards,
Madhav
BR,
Jani.
Regards,
Madhav
+ for_each_dsi_port(port, intel_dsi->ports) {
+ tmp = I915_READ(DPHY_TA_TIMING_PARAM(port));
+ tmp &= ~TA_SURE_TIME_MASK;
+ tmp |= (TA_SURE_OVERRIDE | TA_SURE_TIME(0));
+ I915_WRITE(DPHY_TA_TIMING_PARAM(port), tmp);
+
+ /* shadow register inside display core */
+ tmp = I915_READ(DSI_TA_TIMING_PARAM(port));
+ tmp &= ~TA_SURE_TIME_MASK;
+ tmp |= (TA_SURE_OVERRIDE | TA_SURE_TIME(0));
+ I915_WRITE(DSI_TA_TIMING_PARAM(port), tmp);
+ }
+ }
}
static void gen11_dsi_enable_port_and_phy(struct intel_encoder
*encoder) diff --git a/drivers/gpu/drm/i915/intel_dsi.h
b/drivers/gpu/drm/i915/intel_dsi.h
index 9fd8526..25e7396 100644
--- a/drivers/gpu/drm/i915/intel_dsi.h
+++ b/drivers/gpu/drm/i915/intel_dsi.h
@@ -101,6 +101,7 @@ struct intel_dsi {
u16 init_count;
u32 pclk;
+ u32 bitrate_khz;
u16 burst_mode_ratio;
/* all delays in ms */
diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c
b/drivers/gpu/drm/i915/intel_dsi_vbt.c
index 428290d..a9a98a4 100644
--- a/drivers/gpu/drm/i915/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c
@@ -589,6 +589,7 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi,
u16 panel_id)
intel_dsi->pclk = pclk;
bitrate = (pclk * bpp) / intel_dsi->lane_count;
+ intel_dsi->bitrate_khz = bitrate;
switch (intel_dsi->escape_clk_div) {
case 0:
--
2.7.4
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Ville Syrjälä
Intel
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
