Re: [PATCH 2/2] drm/i915/glk: Enable cold boot for GLK DSI

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> -----Original Message-----
> From: Nikula, Jani
> Sent: Tuesday, May 30, 2017 12:34 PM
> To: Chauhan, Madhav <madhav.chauhan@xxxxxxxxx>; Ville Syrjälä
> <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Conselvan De Oliveira, Ander
> <ander.conselvan.de.oliveira@xxxxxxxxx>; Hiremath, Shashidhar
> <shashidhar.hiremath@xxxxxxxxx>
> Subject: RE:  [PATCH 2/2] drm/i915/glk: Enable cold boot for GLK
> DSI
> 
> On Wed, 24 May 2017, "Chauhan, Madhav" <madhav.chauhan@xxxxxxxxx>
> wrote:
> >> -----Original Message-----
> >> From: Nikula, Jani
> >> Sent: Wednesday, May 24, 2017 7:22 PM
> >> To: Chauhan, Madhav <madhav.chauhan@xxxxxxxxx>; Ville Syrjälä
> >> <ville.syrjala@xxxxxxxxxxxxxxx>
> >> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Conselvan De Oliveira, Ander
> >> <ander.conselvan.de.oliveira@xxxxxxxxx>; Hiremath, Shashidhar
> >> <shashidhar.hiremath@xxxxxxxxx>
> >> Subject: RE:  [PATCH 2/2] drm/i915/glk: Enable cold boot
> >> for GLK DSI
> >>
> >> On Mon, 15 May 2017, "Chauhan, Madhav"
> <madhav.chauhan@xxxxxxxxx>
> >> wrote:
> >> >> -----Original Message-----
> >> >> From: Nikula, Jani
> >> >> Sent: Monday, May 15, 2017 9:19 PM
> >> >> To: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>; Chauhan, Madhav
> >> >> <madhav.chauhan@xxxxxxxxx>
> >> >> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Conselvan De Oliveira, Ander
> >> >> <ander.conselvan.de.oliveira@xxxxxxxxx>; Hiremath, Shashidhar
> >> >> <shashidhar.hiremath@xxxxxxxxx>
> >> >> Subject: Re:  [PATCH 2/2] drm/i915/glk: Enable cold
> >> >> boot for GLK DSI
> >> >>
> >> >> On Tue, 09 May 2017, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> wrote:
> >> >> > On Tue, May 09, 2017 at 06:59:25PM +0530, Madhav Chauhan wrote:
> >> >> >> As per BSEPC, if device ready bit is '0' in enable IO sequence
> >> >> >> then its a cold boot/reset scenario eg: S3/S4 resume. In these
> >> >> >> conditions we need to program certain registers and prepare
> >> >> >> port from the middle of DSI enable sequence otherwise feature
> >> >> >> like S3/S4
> >> doesn't work.
> >> >> >
> >> >> > Can't we just always follow the "cold boot" sequence? Less
> >> >> > codepaths means less bugs.
> >> >>
> >> >> I agree. Madhav?
> >> >
> >> > Cold Boot  scenario represents  when DSI controller/IO is not
> >> > initialized
> >> even once before use  eg:
> >> > 1. Connected HDMI boot with DSI panel 2. S3/S4 While normal
> >> > scenario is:
> >> > 1. Boot with DSI panel without HDMI. DSI will be initialized once
> >> > by GOP/BIOS
> >> >
> >> > If we use cold boot sequence always, normal scenario doesn’t work
> >> > as few registers can’t be Programmed as per cold boot scenario.
> >> > LP_WAKE bit
> >> (MIPI_CTRL REG) is one of the example.
> >> >
> >> > Moreover, current changes works very well for all above scenarios :).
> >>
> >> Well, no. There's a very limited set of registers that can and must
> >> only be programmed in the "cold boot" case. This patch moves all of
> >> intel_dsi_prepare() for glk to only be done in the cold boot case,
> >> but there's a load of registers that aren't restricted in this way,
> >> and need to be programmed on enable regardless of device ready. Seems
> >> to me the change here is too coarse grained.
> >
> > Actually when we do GLK_MIPIIO_ENABLE in device_ready all the
> > registers are restored back When DSI is enabled after disable through
> > software *IF* power is not lost(normal scenario) so we can opt out not
> > to program during normal scenario. Found this in my testing.  Will
> > confirm this with HW team.
> >
> > While for cold boot scenario where power is lost during S3/S4, we need
> > to program all these registers And unfortunately when we program
> > *ONLY* register mentioned in BSPEC in device_ready DSI is not up and
> > Need to program all registers here itself to make it work.
> 
> But this assumes that on enable, when power has not been lost, all the
> registers contain the correct information already. We can't rely on that.

Can we try following then??
glk_dsi_device_ready()
{
	-----
	-----
	Intel_dsi_prepare();	// Call dsi_prepare for both the scenarios i.e. cold boot, normal scenario
	------
	-----
}

> 
> BR,
> Jani.
> 
> 
> 
> >
> >>
> >> BR,
> >> Jani.
> >>
> >> >
> >> >>
> >> >> BR,
> >> >> Jani.
> >> >>
> >> >>
> >> >> >
> >> >> >>
> >> >> >> Signed-off-by: Madhav Chauhan <madhav.chauhan@xxxxxxxxx>
> >> >> >> ---
> >> >> >>  drivers/gpu/drm/i915/intel_dsi.c | 79
> >> >> >> ++++++++++++++++++++++++----------------
> >> >> >>  1 file changed, 48 insertions(+), 31 deletions(-)
> >> >> >>
> >> >> >> diff --git a/drivers/gpu/drm/i915/intel_dsi.c
> >> >> >> b/drivers/gpu/drm/i915/intel_dsi.c
> >> >> >> index fc0ef49..6b68864 100644
> >> >> >> --- a/drivers/gpu/drm/i915/intel_dsi.c
> >> >> >> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> >> >> >> @@ -346,12 +346,17 @@ static bool
> >> >> >> intel_dsi_compute_config(struct
> >> >> intel_encoder *encoder,
> >> >> >>  	return true;
> >> >> >>  }
> >> >> >>
> >> >> >> -static void glk_dsi_device_ready(struct intel_encoder
> >> >> >> *encoder)
> >> >> >> +static void intel_dsi_prepare(struct intel_encoder *intel_encoder,
> >> >> >> +			      struct intel_crtc_state *pipe_config);
> >> >> >> +
> >> >> >> +static void glk_dsi_device_ready(struct intel_encoder *encoder,
> >> >> >> +				 struct intel_crtc_state *pipe_config)
> >> >> >>  {
> >> >> >>  	struct drm_i915_private *dev_priv = to_i915(encoder-
> >base.dev);
> >> >> >>  	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder-
> >base);
> >> >> >>  	enum port port;
> >> >> >>  	u32 tmp, val;
> >> >> >> +	bool cold_boot = false;
> >> >> >>
> >> >> >>  	/* Set the MIPI mode
> >> >> >>  	 * If MIPI_Mode is off, then writing to LP_Wake bit is not
> reflecting.
> >> >> >> @@ -370,7 +375,10 @@ static void glk_dsi_device_ready(struct
> >> >> intel_encoder *encoder)
> >> >> >>  	/* Program LP Wake */
> >> >> >>  	for_each_dsi_port(port, intel_dsi->ports) {
> >> >> >>  		tmp = I915_READ(MIPI_CTRL(port));
> >> >> >> -		tmp |= GLK_LP_WAKE;
> >> >> >> +		if (!(I915_READ(MIPI_DEVICE_READY(port)) &
> >> >> DEVICE_READY))
> >> >> >> +			tmp &= ~GLK_LP_WAKE;
> >> >> >> +		else
> >> >> >> +			tmp |= GLK_LP_WAKE;
> >> >> >>  		I915_WRITE(MIPI_CTRL(port), tmp);
> >> >> >>  	}
> >> >> >>
> >> >> >> @@ -382,6 +390,15 @@ static void glk_dsi_device_ready(struct
> >> >> intel_encoder *encoder)
> >> >> >>  			DRM_ERROR("MIPIO port is powergated\n");
> >> >> >>  	}
> >> >> >>
> >> >> >> +	/* Check if cold boot scenario */
> >> >> >> +	for_each_dsi_port(port, intel_dsi->ports) {
> >> >> >> +		cold_boot |=
> !(I915_READ(MIPI_DEVICE_READY(port)) &
> >> >> >> +
> 	DEVICE_READY);
> >> >> >> +	}
> >> >> >> +
> >> >> >> +	if (cold_boot)
> >> >> >> +		intel_dsi_prepare(encoder, pipe_config);
> >> >> >> +
> >> >> >>  	/* Wait for MIPI PHY status bit to set */
> >> >> >>  	for_each_dsi_port(port, intel_dsi->ports) {
> >> >> >>  		if (intel_wait_for_register(dev_priv,
> >> >> >> @@ -402,34 +419,34 @@ static void glk_dsi_device_ready(struct
> >> >> intel_encoder *encoder)
> >> >> >>  			val |= DEVICE_READY;
> >> >> >>  			I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >>  			usleep_range(10, 15);
> >> >> >> -		}
> >> >> >> -
> >> >> >> -		/* Enter ULPS */
> >> >> >> -		val = I915_READ(MIPI_DEVICE_READY(port));
> >> >> >> -		val &= ~ULPS_STATE_MASK;
> >> >> >> -		val |= (ULPS_STATE_ENTER | DEVICE_READY);
> >> >> >> -		I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >> +		} else {
> >> >> >> +			/* Enter ULPS */
> >> >> >> +			val = I915_READ(MIPI_DEVICE_READY(port));
> >> >> >> +			val &= ~ULPS_STATE_MASK;
> >> >> >> +			val |= (ULPS_STATE_ENTER | DEVICE_READY);
> >> >> >> +			I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >>
> >> >> >> -		/* Wait for ULPS active */
> >> >> >> -		if (intel_wait_for_register(dev_priv,
> >> >> >> +			/* Wait for ULPS active */
> >> >> >> +			if (intel_wait_for_register(dev_priv,
> >> >> >>  				MIPI_CTRL(port),
> GLK_ULPS_NOT_ACTIVE, 0,
> >> >> 20))
> >> >> >> -			DRM_ERROR("ULPS not active\n");
> >> >> >> +				DRM_ERROR("ULPS not active\n");
> >> >> >>
> >> >> >> -		/* Exit ULPS */
> >> >> >> -		val = I915_READ(MIPI_DEVICE_READY(port));
> >> >> >> -		val &= ~ULPS_STATE_MASK;
> >> >> >> -		val |= (ULPS_STATE_EXIT | DEVICE_READY);
> >> >> >> -		I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >> +			/* Exit ULPS */
> >> >> >> +			val = I915_READ(MIPI_DEVICE_READY(port));
> >> >> >> +			val &= ~ULPS_STATE_MASK;
> >> >> >> +			val |= (ULPS_STATE_EXIT | DEVICE_READY);
> >> >> >> +			I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >>
> >> >> >> -		/* Enter Normal Mode */
> >> >> >> -		val = I915_READ(MIPI_DEVICE_READY(port));
> >> >> >> -		val &= ~ULPS_STATE_MASK;
> >> >> >> -		val |= (ULPS_STATE_NORMAL_OPERATION |
> DEVICE_READY);
> >> >> >> -		I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >> +			/* Enter Normal Mode */
> >> >> >> +			val = I915_READ(MIPI_DEVICE_READY(port));
> >> >> >> +			val &= ~ULPS_STATE_MASK;
> >> >> >> +			val |= (ULPS_STATE_NORMAL_OPERATION |
> >> >> DEVICE_READY);
> >> >> >> +			I915_WRITE(MIPI_DEVICE_READY(port), val);
> >> >> >>
> >> >> >> -		tmp = I915_READ(MIPI_CTRL(port));
> >> >> >> -		tmp &= ~GLK_LP_WAKE;
> >> >> >> -		I915_WRITE(MIPI_CTRL(port), tmp);
> >> >> >> +			tmp = I915_READ(MIPI_CTRL(port));
> >> >> >> +			tmp &= ~GLK_LP_WAKE;
> >> >> >> +			I915_WRITE(MIPI_CTRL(port), tmp);
> >> >> >> +		}
> >> >> >>  	}
> >> >> >>
> >> >> >>  	/* Wait for Stop state */
> >> >> >> @@ -515,7 +532,8 @@ static void vlv_dsi_device_ready(struct
> >> >> intel_encoder *encoder)
> >> >> >>  	}
> >> >> >>  }
> >> >> >>
> >> >> >> -static void intel_dsi_device_ready(struct intel_encoder
> >> >> >> *encoder)
> >> >> >> +static void intel_dsi_device_ready(struct intel_encoder *encoder,
> >> >> >> +				   struct intel_crtc_state *pipe_config)
> >> >> >>  {
> >> >> >>  	struct drm_i915_private *dev_priv =
> >> >> >> to_i915(encoder->base.dev);
> >> >> >>
> >> >> >> @@ -524,7 +542,7 @@ static void intel_dsi_device_ready(struct
> >> >> intel_encoder *encoder)
> >> >> >>  	else if (IS_BROXTON(dev_priv))
> >> >> >>  		bxt_dsi_device_ready(encoder);
> >> >> >>  	else if (IS_GEMINILAKE(dev_priv))
> >> >> >> -		glk_dsi_device_ready(encoder);
> >> >> >> +		glk_dsi_device_ready(encoder, pipe_config);
> >> >> >>  }
> >> >> >>
> >> >> >>  static void glk_dsi_enter_low_power_mode(struct intel_encoder
> >> >> >> *encoder) @@ -710,8 +728,6 @@ static void
> >> >> >> intel_dsi_port_disable(struct
> >> >> intel_encoder *encoder)
> >> >> >>  	}
> >> >> >>  }
> >> >> >>
> >> >> >> -static void intel_dsi_prepare(struct intel_encoder *intel_encoder,
> >> >> >> -			      struct intel_crtc_state *pipe_config);
> >> >> >>  static void intel_dsi_unprepare(struct intel_encoder
> >> >> >> *encoder);
> >> >> >>
> >> >> >>  static void intel_dsi_msleep(struct intel_dsi *intel_dsi, int
> >> >> >> msec) @@ -800,7 +816,8 @@ static void
> >> >> >> intel_dsi_pre_enable(struct
> >> >> intel_encoder *encoder,
> >> >> >>  		I915_WRITE(DSPCLK_GATE_D, val);
> >> >> >>  	}
> >> >> >>
> >> >> >> -	intel_dsi_prepare(encoder, pipe_config);
> >> >> >> +	if (!IS_GEMINILAKE(dev_priv))
> >> >> >> +		intel_dsi_prepare(encoder, pipe_config);
> >> >> >>
> >> >> >>  	/* Power on, try both CRC pmic gpio and VBT */
> >> >> >>  	if (intel_dsi->gpio_panel)
> >> >> >> @@ -812,7 +829,7 @@ static void intel_dsi_pre_enable(struct
> >> >> intel_encoder *encoder,
> >> >> >>  	intel_dsi_vbt_exec_sequence(intel_dsi,
> >> >> >> MIPI_SEQ_DEASSERT_RESET);
> >> >> >>
> >> >> >>  	/* Put device in ready state (LP-11) */
> >> >> >> -	intel_dsi_device_ready(encoder);
> >> >> >> +	intel_dsi_device_ready(encoder, pipe_config);
> >> >> >>
> >> >> >>  	/* Send initialization commands in LP mode */
> >> >> >>  	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_INIT_OTP);
> >> >> >> --
> >> >> >> 1.9.1
> >> >> >>
> >> >> >> _______________________________________________
> >> >> >> Intel-gfx mailing list
> >> >> >> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> >> >> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >> >>
> >> >> --
> >> >> Jani Nikula, Intel Open Source Technology Center
> >>
> >> --
> >> Jani Nikula, Intel Open Source Technology Center
> 
> --
> Jani Nikula, Intel Open Source Technology Center
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