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From: Dmitry Osipenko <digetx@gmail.com>
To: "Thierry Reding" <thierry.reding@gmail.com>,
	"Jonathan Hunter" <jonathanh@nvidia.com>,
	"Artur Świgoń" <a.swigon@samsung.com>,
	"Georgi Djakov" <georgi.djakov@linaro.org>,
	"Rob Herring" <robh+dt@kernel.org>
Cc: linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	devicetree@vger.kernel.org
Subject: [PATCH v2 19/22] drm/tegra: dc: Tune up high priority request controls for Tegra20
Date: Mon, 30 Mar 2020 04:09:01 +0300	[thread overview]
Message-ID: <20200330010904.27643-20-digetx@gmail.com> (raw)
In-Reply-To: <20200330010904.27643-1-digetx@gmail.com>

Tegra20 has a high-priority-request control that allows to configure
when display's memory client should perform read requests with a higher
priority (Tegra30+ uses other means like Latency Allowance).

This patch changes the controls configuration in order to get a more
aggressive memory prefetching, which allows to reliably avoid FIFO
underflow when running on a lower memory frequency. This allow us
safely drop the memory bandwidth requirement by about two times in a
most popular use-cases (only one display active, video overlay inactive,
no scaling is done).

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/tegra/dc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index b540ac6ffdc4..564af302a965 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1980,12 +1980,12 @@ static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
 		tegra_dc_writel(dc, value, DC_CMD_INT_POLARITY);
 
 		/* initialize timer */
-		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x20) |
-			WINDOW_B_THRESHOLD(0x20) | WINDOW_C_THRESHOLD(0x20);
+		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x70) |
+			WINDOW_B_THRESHOLD(0x30) | WINDOW_C_THRESHOLD(0x70);
 		tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY);
 
-		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(1) |
-			WINDOW_B_THRESHOLD(1) | WINDOW_C_THRESHOLD(1);
+		value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0) |
+			WINDOW_B_THRESHOLD(0) | WINDOW_C_THRESHOLD(0);
 		tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY_TIMER);
 
 		value = VBLANK_INT | WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |
-- 
2.25.1


  parent reply	other threads:[~2020-03-30  1:10 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-30  1:08 [PATCH v2 00/22] Introduce memory interconnect for NVIDIA Tegra SoCs Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 01/22] dt-bindings: memory: tegra20: mc: Document new interconnect property Dmitry Osipenko
2020-04-10 17:05   ` Rob Herring
2020-03-30  1:08 ` [PATCH v2 02/22] dt-bindings: memory: tegra20: emc: " Dmitry Osipenko
2020-04-10 17:06   ` Rob Herring
2020-03-30  1:08 ` [PATCH v2 03/22] dt-bindings: memory: tegra30: mc: " Dmitry Osipenko
2020-04-10 17:06   ` Rob Herring
2020-03-30  1:08 ` [PATCH v2 04/22] dt-bindings: memory: tegra30: emc: " Dmitry Osipenko
2020-04-10 17:07   ` Rob Herring
2020-03-30  1:08 ` [PATCH v2 05/22] dt-bindings: host1x: Document new interconnect properties Dmitry Osipenko
2020-04-10 17:09   ` Rob Herring
2020-04-10 18:28     ` Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 06/22] dt-bindings: memory: tegra20: Add memory client IDs Dmitry Osipenko
2020-04-10 17:10   ` Rob Herring
2020-03-30  1:08 ` [PATCH v2 07/22] dt-bindings: memory: tegra30: " Dmitry Osipenko
2020-04-10 17:10   ` Rob Herring
2020-03-30  1:08 ` [PATCH v2 08/22] ARM: tegra: Add interconnect properties to Tegra20 device-tree Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 09/22] ARM: tegra: Add interconnect properties to Tegra30 device-tree Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 10/22] interconnect: Relax requirement in of_icc_get_from_provider() Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 11/22] memory: tegra: Register as interconnect provider Dmitry Osipenko
2020-04-13 12:43   ` Georgi Djakov
2020-04-13 15:01     ` Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 12/22] memory: tegra20-emc: Use devm_platform_ioremap_resource Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 13/22] memory: tegra20-emc: Continue probing if timings are missing in device-tree Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 14/22] memory: tegra20-emc: Register as interconnect provider Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 15/22] memory: tegra20-emc: Create tegra20-devfreq device Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 16/22] memory: tegra30-emc: Continue probing if timings are missing in device-tree Dmitry Osipenko
2020-03-30  1:08 ` [PATCH v2 17/22] memory: tegra30-emc: Register as interconnect provider Dmitry Osipenko
2020-04-13 12:44   ` Georgi Djakov
2020-04-13 15:18     ` Dmitry Osipenko
2020-03-30  1:09 ` [PATCH v2 18/22] drm/tegra: dc: Support memory bandwidth management Dmitry Osipenko
2020-03-30  1:09 ` Dmitry Osipenko [this message]
2020-03-30  1:09 ` [PATCH v2 20/22] drm/tegra: dc: Extend debug stats with total number of events Dmitry Osipenko
2020-03-30  1:09 ` [PATCH v2 21/22] ARM: tegra: Enable interconnect API in tegra_defconfig Dmitry Osipenko
2020-03-30  1:09 ` [PATCH v2 22/22] ARM: multi_v7_defconfig: Enable interconnect API Dmitry Osipenko

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