diff mbox

[v8] drm/i915: Enable scanline read based on frame timestamps

Message ID 1506347761-4201-1-git-send-email-vidya.srinivas@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Srinivas, Vidya Sept. 25, 2017, 1:56 p.m. UTC
From: Uma Shankar <uma.shankar@intel.com>

For certain platforms on certain encoders, timings are driven
from port instead of pipe. Thus, we can't rely on pipe scanline
registers to get the timing information. Some cases scanline
register read will not be functional.
This is causing vblank evasion logic to fail since it relies on
scanline, causing atomic update failure warnings.

This patch uses pipe framestamp and current timestamp registers
to calculate scanline. This is an indirect way to get the scanline.
It helps resolve atomic update failure for gen9 dsi platforms.

v2: Addressed Ville and Daniel's review comments. Updated the
register MACROs, handled race condition for register reads,
extracted timings from the hwmode. Removed the dependency on
crtc->config to get the encoder type.

v3: Made get scanline function generic

v4: Addressed Ville's review comments. Added a flag to decide timestamp
based scanline reporting. Changed 64bit variables to u32

v5: Adressed Ville's review comments. Put the scanline compute function
at the place of caller. Removed hwmode flags from uapi and used a local
i915 data structure instead.

v6: Used vblank hwmode to get the timings.

v7: Fixed sparse warnings, indentation and minor review comments.

v8: Limited this only for Gen9 DSI.

Credits-to: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c  |   54 ++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_reg.h  |    9 +++++++
 drivers/gpu/drm/i915/intel_drv.h |    2 ++
 drivers/gpu/drm/i915/intel_dsi.c |    8 ++++++
 4 files changed, 73 insertions(+)

Comments

Saarinen, Jani Sept. 25, 2017, 4:34 p.m. UTC | #1
Hi, 
Ville, trybot also passed for DSI system again : https://intel-gfx-ci.01.org/tree/drm-tip/Trybot_1193/
It did some GEM code on BDW that Vidya can comment but should  not be related to this patch.
Are we good to merge now, finally and get this machine also back to normal pool? 

Br,
Jani

> -----Original Message-----

> From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf

> Of Patchwork

> Sent: maanantai 25. syyskuuta 2017 17.42

> To: Srinivas, Vidya <vidya.srinivas@intel.com>

> Cc: intel-gfx@lists.freedesktop.org

> Subject: [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915: Enable scanline read

> based on frame timestamps

> 

> == Series Details ==

> 

> Series: drm/i915: Enable scanline read based on frame timestamps

> URL   : https://patchwork.freedesktop.org/series/30841/

> State : success

> 

> == Summary ==

> 

> Series 30841v1 drm/i915: Enable scanline read based on frame timestamps

> https://patchwork.freedesktop.org/api/1.0/series/30841/revisions/1/mbox/

> 

> Test chamelium:

>         Subgroup dp-edid-read:

>                 pass       -> FAIL       (fi-kbl-7500u) fdo#102672

> Test kms_pipe_crc_basic:

>         Subgroup suspend-read-crc-pipe-b:

>                 dmesg-warn -> PASS       (fi-skl-6770hq)

> Test pm_rpm:

>         Subgroup basic-rte:

>                 dmesg-warn -> PASS       (fi-cfl-s) fdo#102294

> Test drv_module_reload:

>         Subgroup basic-no-display:

>                 pass       -> DMESG-WARN (fi-glk-1) fdo#102777

> 

> fdo#102672 https://bugs.freedesktop.org/show_bug.cgi?id=102672

> fdo#102294 https://bugs.freedesktop.org/show_bug.cgi?id=102294

> fdo#102777 https://bugs.freedesktop.org/show_bug.cgi?id=102777

> 

> fi-bdw-5557u     total:289  pass:268  dwarn:0   dfail:0   fail:0   skip:21

> time:448s

> fi-bdw-gvtdvm    total:289  pass:265  dwarn:0   dfail:0   fail:0   skip:24

> time:464s

> fi-blb-e6850     total:289  pass:224  dwarn:1   dfail:0   fail:0   skip:64

> time:419s

> fi-bsw-n3050     total:289  pass:243  dwarn:0   dfail:0   fail:0   skip:46

> time:516s

> fi-bwr-2160      total:289  pass:184  dwarn:0   dfail:0   fail:0   skip:105

> time:279s

> fi-bxt-j4205     total:289  pass:260  dwarn:0   dfail:0   fail:0   skip:29  time:501s

> fi-byt-j1900     total:289  pass:254  dwarn:1   dfail:0   fail:0   skip:34  time:486s

> fi-byt-n2820     total:289  pass:250  dwarn:1   dfail:0   fail:0   skip:38

> time:491s

> fi-cfl-s         total:289  pass:223  dwarn:34  dfail:0   fail:0   skip:32  time:544s

> fi-cnl-y         total:289  pass:256  dwarn:0   dfail:0   fail:6   skip:27  time:645s

> fi-elk-e7500     total:289  pass:230  dwarn:0   dfail:0   fail:0   skip:59

> time:416s

> fi-glk-1         total:289  pass:259  dwarn:1   dfail:0   fail:0   skip:29  time:558s

> fi-hsw-4770      total:289  pass:263  dwarn:0   dfail:0   fail:0   skip:26

> time:423s

> fi-hsw-4770r     total:289  pass:263  dwarn:0   dfail:0   fail:0   skip:26

> time:403s

> fi-ilk-650       total:289  pass:229  dwarn:0   dfail:0   fail:0   skip:60  time:432s

> fi-ivb-3520m     total:289  pass:261  dwarn:0   dfail:0   fail:0   skip:28

> time:492s

> fi-ivb-3770      total:289  pass:261  dwarn:0   dfail:0   fail:0   skip:28  time:464s

> fi-kbl-7500u     total:289  pass:263  dwarn:1   dfail:0   fail:1   skip:24

> time:467s

> fi-kbl-7560u     total:289  pass:270  dwarn:0   dfail:0   fail:0   skip:19

> time:579s

> fi-kbl-r         total:289  pass:262  dwarn:0   dfail:0   fail:0   skip:27  time:596s

> fi-pnv-d510      total:289  pass:223  dwarn:1   dfail:0   fail:0   skip:65

> time:544s

> fi-skl-6260u     total:289  pass:269  dwarn:0   dfail:0   fail:0   skip:20  time:444s

> fi-skl-6700k     total:289  pass:265  dwarn:0   dfail:0   fail:0   skip:24  time:756s

> fi-skl-6770hq    total:289  pass:269  dwarn:0   dfail:0   fail:0   skip:20

> time:496s

> fi-skl-gvtdvm    total:289  pass:266  dwarn:0   dfail:0   fail:0   skip:23

> time:473s

> fi-snb-2520m     total:289  pass:251  dwarn:0   dfail:0   fail:0   skip:38

> time:568s

> fi-snb-2600      total:289  pass:250  dwarn:0   dfail:0   fail:0   skip:39

> time:413s

> 

> 0b65077382608db179cb5afafecf4a0edd35c2fe drm-tip: 2017y-09m-25d-

> 13h-55m-18s UTC integration manifest

> 1ac5c013f6d8 drm/i915: Enable scanline read based on frame timestamps

> 

> == Logs ==

> 

> For more details see: https://intel-gfx-ci.01.org/tree/drm-

> tip/Patchwork_5805/

> _______________________________________________

> Intel-gfx mailing list

> Intel-gfx@lists.freedesktop.org

> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Shankar, Uma Sept. 25, 2017, 5:26 p.m. UTC | #2
>-----Original Message-----

>From: Srinivas, Vidya

>Sent: Monday, September 25, 2017 7:26 PM

>To: intel-gfx@lists.freedesktop.org

>Cc: Syrjala, Ville <ville.syrjala@intel.com>; Kahola, Mika

><mika.kahola@intel.com>; Kamath, Sunil <sunil.kamath@intel.com>; Shankar,

>Uma <uma.shankar@intel.com>; Konduru, Chandra

><chandra.konduru@intel.com>; Srinivas, Vidya <vidya.srinivas@intel.com>

>Subject: [PATCH v8] drm/i915: Enable scanline read based on frame timestamps

>

>From: Uma Shankar <uma.shankar@intel.com>

>

>For certain platforms on certain encoders, timings are driven from port instead of

>pipe. Thus, we can't rely on pipe scanline registers to get the timing information.

>Some cases scanline register read will not be functional.

>This is causing vblank evasion logic to fail since it relies on scanline, causing

>atomic update failure warnings.

>

>This patch uses pipe framestamp and current timestamp registers to calculate

>scanline. This is an indirect way to get the scanline.

>It helps resolve atomic update failure for gen9 dsi platforms.

>

>v2: Addressed Ville and Daniel's review comments. Updated the register MACROs,

>handled race condition for register reads, extracted timings from the hwmode.

>Removed the dependency on

>crtc->config to get the encoder type.

>

>v3: Made get scanline function generic

>

>v4: Addressed Ville's review comments. Added a flag to decide timestamp based

>scanline reporting. Changed 64bit variables to u32

>

>v5: Adressed Ville's review comments. Put the scanline compute function at the

>place of caller. Removed hwmode flags from uapi and used a local

>i915 data structure instead.

>

>v6: Used vblank hwmode to get the timings.

>

>v7: Fixed sparse warnings, indentation and minor review comments.

>

>v8: Limited this only for Gen9 DSI.

>


This patch is passing on try-bot.  Below are the results.
Series: drm/i915: Enable scanline read based on frame timestamps (rev5)
URL   : https://patchwork.freedesktop.org/series/30575/
State : success

This can be taken for merge now.

Thanks Ville for the support on this one. 

Regards,
Uma Shankar

>Credits-to: Ville Syrjälä <ville.syrjala@linux.intel.com>

>Signed-off-by: Uma Shankar <uma.shankar@intel.com>

>Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>

>Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>

>Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

>---

> drivers/gpu/drm/i915/i915_irq.c  |   54

>++++++++++++++++++++++++++++++++++++++

> drivers/gpu/drm/i915/i915_reg.h  |    9 +++++++

> drivers/gpu/drm/i915/intel_drv.h |    2 ++

> drivers/gpu/drm/i915/intel_dsi.c |    8 ++++++

> 4 files changed, 73 insertions(+)

>

>diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c

>index 91a2c5d..0d3fa70 100644

>--- a/drivers/gpu/drm/i915/i915_irq.c

>+++ b/drivers/gpu/drm/i915/i915_irq.c

>@@ -772,6 +772,57 @@ static u32 g4x_get_vblank_counter(struct drm_device

>*dev, unsigned int pipe)

> 	return I915_READ(PIPE_FRMCOUNT_G4X(pipe));

> }

>

>+/*

>+ * On certain encoders on certain platforms, pipe

>+ * scanline register will not work to get the scanline,

>+ * since the timings are driven from the PORT or issues

>+ * with scanline register updates.

>+ * This function will use Framestamp and current

>+ * timestamp registers to calculate the scanline.

>+ */

>+static u32 __intel_get_crtc_scanline_from_timestamp(struct intel_crtc

>+*crtc) {

>+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

>+	struct drm_vblank_crtc *vblank =

>+		&crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];

>+	const struct drm_display_mode *mode = &vblank->hwmode;

>+	u32 vblank_start = mode->crtc_vblank_start;

>+	u32 vtotal = mode->crtc_vtotal;

>+	u32 htotal = mode->crtc_htotal;

>+	u32 clock = mode->crtc_clock;

>+	u32 scanline, scan_prev_time, scan_curr_time, scan_post_time;

>+

>+	/*

>+	 * To avoid the race condition where we might cross into the

>+	 * next vblank just between the PIPE_FRMTMSTMP and TIMESTAMP_CTR

>+	 * reads. We make sure we read PIPE_FRMTMSTMP and

>TIMESTAMP_CTR

>+	 * during the same frame.

>+	 */

>+	do {

>+		/*

>+		 * This field provides read back of the display

>+		 * pipe frame time stamp. The time stamp value

>+		 * is sampled at every start of vertical blank.

>+		 */

>+		scan_prev_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc-

>>pipe));

>+

>+		/*

>+		 * The TIMESTAMP_CTR register has the current

>+		 * time stamp value.

>+		 */

>+		scan_curr_time = I915_READ_FW(IVB_TIMESTAMP_CTR);

>+

>+		scan_post_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc-

>>pipe));

>+	} while (scan_post_time != scan_prev_time);

>+

>+	scanline = div_u64(mul_u32_u32(scan_curr_time - scan_prev_time,

>+					clock), 1000 * htotal);

>+	scanline = min(scanline, vtotal - 1);

>+	scanline = (scanline + vblank_start) % vtotal;

>+

>+	return scanline;

>+}

>+

> /* I915_READ_FW, only for fast reads of display block, no need for forcewake

>etc. */  static int __intel_get_crtc_scanline(struct intel_crtc *crtc)  { @@ -788,6

>+839,9 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)

> 	vblank = &crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];

> 	mode = &vblank->hwmode;

>

>+	if (mode->private_flags &

>I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP)

>+		return __intel_get_crtc_scanline_from_timestamp(crtc);

>+

> 	vtotal = mode->crtc_vtotal;

> 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)

> 		vtotal /= 2;

>diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h

>index 9f03cd0..fbd00cc 100644

>--- a/drivers/gpu/drm/i915/i915_reg.h

>+++ b/drivers/gpu/drm/i915/i915_reg.h

>@@ -8804,6 +8804,15 @@ enum skl_power_gate {

> #define MIPIO_TXESC_CLK_DIV2			_MMIO(0x160008)

> #define  GLK_TX_ESC_CLK_DIV2_MASK			0x3FF

>

>+/* Gen4+ Timestamp and Pipe Frame time stamp registers */

>+#define GEN4_TIMESTAMP		_MMIO(0x2358)

>+#define ILK_TIMESTAMP_HI	_MMIO(0x70070)

>+#define IVB_TIMESTAMP_CTR	_MMIO(0x44070)

>+

>+#define _PIPE_FRMTMSTMP_A		0x70048

>+#define PIPE_FRMTMSTMP(pipe)		\

>+			_MMIO_PIPE2(pipe, _PIPE_FRMTMSTMP_A)

>+

> /* BXT MIPI clock controls */

> #define BXT_MAX_VAR_OUTPUT_KHZ			39500

>

>diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h

>index 3078076..4170490 100644

>--- a/drivers/gpu/drm/i915/intel_drv.h

>+++ b/drivers/gpu/drm/i915/intel_drv.h

>@@ -494,6 +494,8 @@ struct intel_crtc_scaler_state {

>

> /* drm_mode->private_flags */

> #define I915_MODE_FLAG_INHERITED 1

>+/* Flag to get scanline using frame time stamps */ #define

>+I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP (1<<1)

>

> struct intel_pipe_wm {

> 	struct intel_wm_level wm[5];

>diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c

>index 578254a..20a7b00 100644

>--- a/drivers/gpu/drm/i915/intel_dsi.c

>+++ b/drivers/gpu/drm/i915/intel_dsi.c

>@@ -330,6 +330,10 @@ static bool intel_dsi_compute_config(struct

>intel_encoder *encoder,

> 	adjusted_mode->flags = 0;

>

> 	if (IS_GEN9_LP(dev_priv)) {

>+		/* Enable Frame time stamp based scanline reporting */

>+		adjusted_mode->private_flags |=

>+			I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;

>+

> 		/* Dual link goes to DSI transcoder A. */

> 		if (intel_dsi->ports == BIT(PORT_C))

> 			pipe_config->cpu_transcoder = TRANSCODER_DSI_C;

>@@ -1102,6 +1106,10 @@ static void bxt_dsi_get_pipe_config(struct

>intel_encoder *encoder,

> 				pixel_format_from_register_bits(fmt));

> 	bpp = pipe_config->pipe_bpp;

>

>+	/* Enable Frame time stamo based scanline reporting */

>+	adjusted_mode->private_flags |=

>+			I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;

>+

> 	/* In terms of pixels */

> 	adjusted_mode->crtc_hdisplay =

> 				I915_READ(BXT_MIPI_TRANS_HACTIVE(port));

>--

>1.7.9.5
Saarinen, Jani Sept. 25, 2017, 5:27 p.m. UTC | #3
HI,
> -----Original Message-----

> From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf

> Of Saarinen, Jani

> Sent: maanantai 25. syyskuuta 2017 19.34

> To: intel-gfx@lists.freedesktop.org; Srinivas, Vidya

> <vidya.srinivas@intel.com>; Ville Syrjälä <ville.syrjala@linux.intel.com>

> Subject: Re: [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915: Enable scanline

> read based on frame timestamps

> 

> Hi,

> Ville, trybot also passed for DSI system again : https://intel-gfx-

> ci.01.org/tree/drm-tip/Trybot_1193/

> It did hit some GEM code on BDW that Vidya can comment but should  not be

> related to this patch.

Now trybot passed on second run: https://intel-gfx-ci.01.org/tree/drm-tip/Trybot_1195/
I guess good enough? 

> Are we good to merge now, finally and get this machine also back to normal

> pool?

> 

> Br,

> Jani

> 

> > -----Original Message-----

> > From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On

> > Behalf Of Patchwork

> > Sent: maanantai 25. syyskuuta 2017 17.42

> > To: Srinivas, Vidya <vidya.srinivas@intel.com>

> > Cc: intel-gfx@lists.freedesktop.org

> > Subject: [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915: Enable

> > scanline read based on frame timestamps

> >

> > == Series Details ==

> >

> > Series: drm/i915: Enable scanline read based on frame timestamps

> > URL   : https://patchwork.freedesktop.org/series/30841/

> > State : success

> >

> > == Summary ==

> >

> > Series 30841v1 drm/i915: Enable scanline read based on frame

> > timestamps

> > https://patchwork.freedesktop.org/api/1.0/series/30841/revisions/1/mbo

> > x/

> >

> > Test chamelium:

> >         Subgroup dp-edid-read:

> >                 pass       -> FAIL       (fi-kbl-7500u) fdo#102672

> > Test kms_pipe_crc_basic:

> >         Subgroup suspend-read-crc-pipe-b:

> >                 dmesg-warn -> PASS       (fi-skl-6770hq)

> > Test pm_rpm:

> >         Subgroup basic-rte:

> >                 dmesg-warn -> PASS       (fi-cfl-s) fdo#102294

> > Test drv_module_reload:

> >         Subgroup basic-no-display:

> >                 pass       -> DMESG-WARN (fi-glk-1) fdo#102777

> >

> > fdo#102672 https://bugs.freedesktop.org/show_bug.cgi?id=102672

> > fdo#102294 https://bugs.freedesktop.org/show_bug.cgi?id=102294

> > fdo#102777 https://bugs.freedesktop.org/show_bug.cgi?id=102777

> >

> > fi-bdw-5557u     total:289  pass:268  dwarn:0   dfail:0   fail:0   skip:21

> > time:448s

> > fi-bdw-gvtdvm    total:289  pass:265  dwarn:0   dfail:0   fail:0   skip:24

> > time:464s

> > fi-blb-e6850     total:289  pass:224  dwarn:1   dfail:0   fail:0   skip:64

> > time:419s

> > fi-bsw-n3050     total:289  pass:243  dwarn:0   dfail:0   fail:0   skip:46

> > time:516s

> > fi-bwr-2160      total:289  pass:184  dwarn:0   dfail:0   fail:0   skip:105

> > time:279s

> > fi-bxt-j4205     total:289  pass:260  dwarn:0   dfail:0   fail:0   skip:29

> time:501s

> > fi-byt-j1900     total:289  pass:254  dwarn:1   dfail:0   fail:0   skip:34

> time:486s

> > fi-byt-n2820     total:289  pass:250  dwarn:1   dfail:0   fail:0   skip:38

> > time:491s

> > fi-cfl-s         total:289  pass:223  dwarn:34  dfail:0   fail:0   skip:32  time:544s

> > fi-cnl-y         total:289  pass:256  dwarn:0   dfail:0   fail:6   skip:27  time:645s

> > fi-elk-e7500     total:289  pass:230  dwarn:0   dfail:0   fail:0   skip:59

> > time:416s

> > fi-glk-1         total:289  pass:259  dwarn:1   dfail:0   fail:0   skip:29  time:558s

> > fi-hsw-4770      total:289  pass:263  dwarn:0   dfail:0   fail:0   skip:26

> > time:423s

> > fi-hsw-4770r     total:289  pass:263  dwarn:0   dfail:0   fail:0   skip:26

> > time:403s

> > fi-ilk-650       total:289  pass:229  dwarn:0   dfail:0   fail:0   skip:60  time:432s

> > fi-ivb-3520m     total:289  pass:261  dwarn:0   dfail:0   fail:0   skip:28

> > time:492s

> > fi-ivb-3770      total:289  pass:261  dwarn:0   dfail:0   fail:0   skip:28

> time:464s

> > fi-kbl-7500u     total:289  pass:263  dwarn:1   dfail:0   fail:1   skip:24

> > time:467s

> > fi-kbl-7560u     total:289  pass:270  dwarn:0   dfail:0   fail:0   skip:19

> > time:579s

> > fi-kbl-r         total:289  pass:262  dwarn:0   dfail:0   fail:0   skip:27  time:596s

> > fi-pnv-d510      total:289  pass:223  dwarn:1   dfail:0   fail:0   skip:65

> > time:544s

> > fi-skl-6260u     total:289  pass:269  dwarn:0   dfail:0   fail:0   skip:20

> time:444s

> > fi-skl-6700k     total:289  pass:265  dwarn:0   dfail:0   fail:0   skip:24

> time:756s

> > fi-skl-6770hq    total:289  pass:269  dwarn:0   dfail:0   fail:0   skip:20

> > time:496s

> > fi-skl-gvtdvm    total:289  pass:266  dwarn:0   dfail:0   fail:0   skip:23

> > time:473s

> > fi-snb-2520m     total:289  pass:251  dwarn:0   dfail:0   fail:0   skip:38

> > time:568s

> > fi-snb-2600      total:289  pass:250  dwarn:0   dfail:0   fail:0   skip:39

> > time:413s

> >

> > 0b65077382608db179cb5afafecf4a0edd35c2fe drm-tip: 2017y-09m-25d-

> > 13h-55m-18s UTC integration manifest

> > 1ac5c013f6d8 drm/i915: Enable scanline read based on frame timestamps

> >

> > == Logs ==

> >

> > For more details see: https://intel-gfx-ci.01.org/tree/drm-

> > tip/Patchwork_5805


Jani Saarinen
Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Jani Nikula Sept. 26, 2017, 8:03 a.m. UTC | #4
On Mon, 25 Sep 2017, Vidya Srinivas <vidya.srinivas@intel.com> wrote:
> From: Uma Shankar <uma.shankar@intel.com>
>
> For certain platforms on certain encoders, timings are driven
> from port instead of pipe. Thus, we can't rely on pipe scanline
> registers to get the timing information. Some cases scanline
> register read will not be functional.
> This is causing vblank evasion logic to fail since it relies on
> scanline, causing atomic update failure warnings.
>
> This patch uses pipe framestamp and current timestamp registers
> to calculate scanline. This is an indirect way to get the scanline.
> It helps resolve atomic update failure for gen9 dsi platforms.
>
> v2: Addressed Ville and Daniel's review comments. Updated the
> register MACROs, handled race condition for register reads,
> extracted timings from the hwmode. Removed the dependency on
> crtc->config to get the encoder type.
>
> v3: Made get scanline function generic
>
> v4: Addressed Ville's review comments. Added a flag to decide timestamp
> based scanline reporting. Changed 64bit variables to u32
>
> v5: Adressed Ville's review comments. Put the scanline compute function
> at the place of caller. Removed hwmode flags from uapi and used a local
> i915 data structure instead.
>
> v6: Used vblank hwmode to get the timings.
>
> v7: Fixed sparse warnings, indentation and minor review comments.
>
> v8: Limited this only for Gen9 DSI.
>
> Credits-to: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Pushed to dinq, thanks for the patch and review.

BR,
Jani.

> ---
>  drivers/gpu/drm/i915/i915_irq.c  |   54 ++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h  |    9 +++++++
>  drivers/gpu/drm/i915/intel_drv.h |    2 ++
>  drivers/gpu/drm/i915/intel_dsi.c |    8 ++++++
>  4 files changed, 73 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 91a2c5d..0d3fa70 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -772,6 +772,57 @@ static u32 g4x_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
>  	return I915_READ(PIPE_FRMCOUNT_G4X(pipe));
>  }
>  
> +/*
> + * On certain encoders on certain platforms, pipe
> + * scanline register will not work to get the scanline,
> + * since the timings are driven from the PORT or issues
> + * with scanline register updates.
> + * This function will use Framestamp and current
> + * timestamp registers to calculate the scanline.
> + */
> +static u32 __intel_get_crtc_scanline_from_timestamp(struct intel_crtc *crtc)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +	struct drm_vblank_crtc *vblank =
> +		&crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
> +	const struct drm_display_mode *mode = &vblank->hwmode;
> +	u32 vblank_start = mode->crtc_vblank_start;
> +	u32 vtotal = mode->crtc_vtotal;
> +	u32 htotal = mode->crtc_htotal;
> +	u32 clock = mode->crtc_clock;
> +	u32 scanline, scan_prev_time, scan_curr_time, scan_post_time;
> +
> +	/*
> +	 * To avoid the race condition where we might cross into the
> +	 * next vblank just between the PIPE_FRMTMSTMP and TIMESTAMP_CTR
> +	 * reads. We make sure we read PIPE_FRMTMSTMP and TIMESTAMP_CTR
> +	 * during the same frame.
> +	 */
> +	do {
> +		/*
> +		 * This field provides read back of the display
> +		 * pipe frame time stamp. The time stamp value
> +		 * is sampled at every start of vertical blank.
> +		 */
> +		scan_prev_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc->pipe));
> +
> +		/*
> +		 * The TIMESTAMP_CTR register has the current
> +		 * time stamp value.
> +		 */
> +		scan_curr_time = I915_READ_FW(IVB_TIMESTAMP_CTR);
> +
> +		scan_post_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc->pipe));
> +	} while (scan_post_time != scan_prev_time);
> +
> +	scanline = div_u64(mul_u32_u32(scan_curr_time - scan_prev_time,
> +					clock), 1000 * htotal);
> +	scanline = min(scanline, vtotal - 1);
> +	scanline = (scanline + vblank_start) % vtotal;
> +
> +	return scanline;
> +}
> +
>  /* I915_READ_FW, only for fast reads of display block, no need for forcewake etc. */
>  static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
>  {
> @@ -788,6 +839,9 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
>  	vblank = &crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
>  	mode = &vblank->hwmode;
>  
> +	if (mode->private_flags & I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP)
> +		return __intel_get_crtc_scanline_from_timestamp(crtc);
> +
>  	vtotal = mode->crtc_vtotal;
>  	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
>  		vtotal /= 2;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 9f03cd0..fbd00cc 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8804,6 +8804,15 @@ enum skl_power_gate {
>  #define MIPIO_TXESC_CLK_DIV2			_MMIO(0x160008)
>  #define  GLK_TX_ESC_CLK_DIV2_MASK			0x3FF
>  
> +/* Gen4+ Timestamp and Pipe Frame time stamp registers */
> +#define GEN4_TIMESTAMP		_MMIO(0x2358)
> +#define ILK_TIMESTAMP_HI	_MMIO(0x70070)
> +#define IVB_TIMESTAMP_CTR	_MMIO(0x44070)
> +
> +#define _PIPE_FRMTMSTMP_A		0x70048
> +#define PIPE_FRMTMSTMP(pipe)		\
> +			_MMIO_PIPE2(pipe, _PIPE_FRMTMSTMP_A)
> +
>  /* BXT MIPI clock controls */
>  #define BXT_MAX_VAR_OUTPUT_KHZ			39500
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 3078076..4170490 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -494,6 +494,8 @@ struct intel_crtc_scaler_state {
>  
>  /* drm_mode->private_flags */
>  #define I915_MODE_FLAG_INHERITED 1
> +/* Flag to get scanline using frame time stamps */
> +#define I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP (1<<1)
>  
>  struct intel_pipe_wm {
>  	struct intel_wm_level wm[5];
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index 578254a..20a7b00 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -330,6 +330,10 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
>  	adjusted_mode->flags = 0;
>  
>  	if (IS_GEN9_LP(dev_priv)) {
> +		/* Enable Frame time stamp based scanline reporting */
> +		adjusted_mode->private_flags |=
> +			I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;
> +
>  		/* Dual link goes to DSI transcoder A. */
>  		if (intel_dsi->ports == BIT(PORT_C))
>  			pipe_config->cpu_transcoder = TRANSCODER_DSI_C;
> @@ -1102,6 +1106,10 @@ static void bxt_dsi_get_pipe_config(struct intel_encoder *encoder,
>  				pixel_format_from_register_bits(fmt));
>  	bpp = pipe_config->pipe_bpp;
>  
> +	/* Enable Frame time stamo based scanline reporting */
> +	adjusted_mode->private_flags |=
> +			I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;
> +
>  	/* In terms of pixels */
>  	adjusted_mode->crtc_hdisplay =
>  				I915_READ(BXT_MIPI_TRANS_HACTIVE(port));
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 91a2c5d..0d3fa70 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -772,6 +772,57 @@  static u32 g4x_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
 	return I915_READ(PIPE_FRMCOUNT_G4X(pipe));
 }
 
+/*
+ * On certain encoders on certain platforms, pipe
+ * scanline register will not work to get the scanline,
+ * since the timings are driven from the PORT or issues
+ * with scanline register updates.
+ * This function will use Framestamp and current
+ * timestamp registers to calculate the scanline.
+ */
+static u32 __intel_get_crtc_scanline_from_timestamp(struct intel_crtc *crtc)
+{
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	struct drm_vblank_crtc *vblank =
+		&crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
+	const struct drm_display_mode *mode = &vblank->hwmode;
+	u32 vblank_start = mode->crtc_vblank_start;
+	u32 vtotal = mode->crtc_vtotal;
+	u32 htotal = mode->crtc_htotal;
+	u32 clock = mode->crtc_clock;
+	u32 scanline, scan_prev_time, scan_curr_time, scan_post_time;
+
+	/*
+	 * To avoid the race condition where we might cross into the
+	 * next vblank just between the PIPE_FRMTMSTMP and TIMESTAMP_CTR
+	 * reads. We make sure we read PIPE_FRMTMSTMP and TIMESTAMP_CTR
+	 * during the same frame.
+	 */
+	do {
+		/*
+		 * This field provides read back of the display
+		 * pipe frame time stamp. The time stamp value
+		 * is sampled at every start of vertical blank.
+		 */
+		scan_prev_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc->pipe));
+
+		/*
+		 * The TIMESTAMP_CTR register has the current
+		 * time stamp value.
+		 */
+		scan_curr_time = I915_READ_FW(IVB_TIMESTAMP_CTR);
+
+		scan_post_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc->pipe));
+	} while (scan_post_time != scan_prev_time);
+
+	scanline = div_u64(mul_u32_u32(scan_curr_time - scan_prev_time,
+					clock), 1000 * htotal);
+	scanline = min(scanline, vtotal - 1);
+	scanline = (scanline + vblank_start) % vtotal;
+
+	return scanline;
+}
+
 /* I915_READ_FW, only for fast reads of display block, no need for forcewake etc. */
 static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
 {
@@ -788,6 +839,9 @@  static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
 	vblank = &crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
 	mode = &vblank->hwmode;
 
+	if (mode->private_flags & I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP)
+		return __intel_get_crtc_scanline_from_timestamp(crtc);
+
 	vtotal = mode->crtc_vtotal;
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		vtotal /= 2;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9f03cd0..fbd00cc 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8804,6 +8804,15 @@  enum skl_power_gate {
 #define MIPIO_TXESC_CLK_DIV2			_MMIO(0x160008)
 #define  GLK_TX_ESC_CLK_DIV2_MASK			0x3FF
 
+/* Gen4+ Timestamp and Pipe Frame time stamp registers */
+#define GEN4_TIMESTAMP		_MMIO(0x2358)
+#define ILK_TIMESTAMP_HI	_MMIO(0x70070)
+#define IVB_TIMESTAMP_CTR	_MMIO(0x44070)
+
+#define _PIPE_FRMTMSTMP_A		0x70048
+#define PIPE_FRMTMSTMP(pipe)		\
+			_MMIO_PIPE2(pipe, _PIPE_FRMTMSTMP_A)
+
 /* BXT MIPI clock controls */
 #define BXT_MAX_VAR_OUTPUT_KHZ			39500
 
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 3078076..4170490 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -494,6 +494,8 @@  struct intel_crtc_scaler_state {
 
 /* drm_mode->private_flags */
 #define I915_MODE_FLAG_INHERITED 1
+/* Flag to get scanline using frame time stamps */
+#define I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP (1<<1)
 
 struct intel_pipe_wm {
 	struct intel_wm_level wm[5];
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 578254a..20a7b00 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -330,6 +330,10 @@  static bool intel_dsi_compute_config(struct intel_encoder *encoder,
 	adjusted_mode->flags = 0;
 
 	if (IS_GEN9_LP(dev_priv)) {
+		/* Enable Frame time stamp based scanline reporting */
+		adjusted_mode->private_flags |=
+			I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;
+
 		/* Dual link goes to DSI transcoder A. */
 		if (intel_dsi->ports == BIT(PORT_C))
 			pipe_config->cpu_transcoder = TRANSCODER_DSI_C;
@@ -1102,6 +1106,10 @@  static void bxt_dsi_get_pipe_config(struct intel_encoder *encoder,
 				pixel_format_from_register_bits(fmt));
 	bpp = pipe_config->pipe_bpp;
 
+	/* Enable Frame time stamo based scanline reporting */
+	adjusted_mode->private_flags |=
+			I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;
+
 	/* In terms of pixels */
 	adjusted_mode->crtc_hdisplay =
 				I915_READ(BXT_MIPI_TRANS_HACTIVE(port));