linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v6 0/4] drm/panfrost: Add support for mt8183 GPU
@ 2021-01-05  0:11 Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 1/4] dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183 Nicolas Boichat
                   ` (3 more replies)
  0 siblings, 4 replies; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-05  0:11 UTC (permalink / raw)
  To: Rob Herring, Steven Price, Alyssa Rosenzweig
  Cc: hsinyi, hoegsberg, fshao, boris.brezillon, Nicolas Boichat,
	Daniel Vetter, David Airlie, Matthias Brugger, Rob Herring,
	Tomeu Vizoso, devicetree, dri-devel, linux-arm-kernel,
	linux-kernel, linux-mediatek

Hi!

Follow-up on the v5 [1], things have gotten significantly
better in the last 9 months, thanks to the efforts on Bifrost
support by the Collabora team (and probably others I'm not
aware of).

I've been testing this series on a MT8183/kukui device, with a
chromeos-5.10 kernel [2], and got basic Chromium OS UI up with
mesa 20.3.2 (lots of artifacts though).

devfreq is currently not supported, as we'll need:
 - Clock core support for switching the GPU core clock (see 2/4).
 - Platform-specific handling of the 2-regulator (see 3/4).

Since the latter is easy to detect, patch 3/4 just disables
devfreq if the more than one regulator is specified in the
compatible matching table.

[1] https://patchwork.kernel.org/project/linux-mediatek/cover/20200306041345.259332-1-drinkcat@chromium.org/
[2] https://crrev.com/c/2608070

Changes in v6:
 - Rebased, actually tested with recent mesa driver.

Nicolas Boichat (4):
  dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183
  arm64: dts: mt8183: Add node for the Mali GPU
  drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
  drm/panfrost: Add mt8183-mali compatible string

 .../bindings/gpu/arm,mali-bifrost.yaml        |  25 +++++
 arch/arm64/boot/dts/mediatek/mt8183-evb.dts   |   6 +
 .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi |   6 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      | 105 ++++++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_devfreq.c   |   9 ++
 drivers/gpu/drm/panfrost/panfrost_drv.c       |  10 ++
 6 files changed, 161 insertions(+)

-- 
2.29.2.729.g45daf8777d-goog


^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v6 1/4] dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183
  2021-01-05  0:11 [PATCH v6 0/4] drm/panfrost: Add support for mt8183 GPU Nicolas Boichat
@ 2021-01-05  0:11 ` Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 2/4] arm64: dts: mt8183: Add node for the Mali GPU Nicolas Boichat
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-05  0:11 UTC (permalink / raw)
  To: Rob Herring, Steven Price, Alyssa Rosenzweig
  Cc: hsinyi, hoegsberg, fshao, boris.brezillon, Nicolas Boichat,
	Daniel Vetter, David Airlie, Matthias Brugger, Rob Herring,
	devicetree, dri-devel, linux-arm-kernel, linux-kernel,
	linux-mediatek

Define a compatible string for the Mali Bifrost GPU found in
Mediatek's MT8183 SoCs.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
---

Changes in v6:
 - Rebased, actually tested with recent mesa driver.
 - No change

Changes in v5:
 - Rename "2d" power domain to "core2"

Changes in v4:
 - Add power-domain-names description
   (kept Alyssa's reviewed-by as the change is minor)

Changes in v3:
 - No change

 .../bindings/gpu/arm,mali-bifrost.yaml        | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml b/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
index 184492162e7e..71b613ee5bd7 100644
--- a/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
+++ b/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
@@ -17,6 +17,7 @@ properties:
     items:
       - enum:
           - amlogic,meson-g12a-mali
+          - mediatek,mt8183-mali
           - realtek,rtd1619-mali
           - rockchip,px30-mali
       - const: arm,mali-bifrost # Mali Bifrost GPU model/revision is fully discoverable
@@ -87,6 +88,30 @@ allOf:
     then:
       required:
         - resets
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: mediatek,mt8183-mali
+    then:
+      properties:
+        sram-supply: true
+        power-domains:
+          description:
+            List of phandle and PM domain specifier as documented in
+            Documentation/devicetree/bindings/power/power_domain.txt
+          minItems: 3
+          maxItems: 3
+        power-domain-names:
+          items:
+            - const: core0
+            - const: core1
+            - const: core2
+
+      required:
+        - sram-supply
+        - power-domains
+        - power-domains-names
 
 examples:
   - |
-- 
2.29.2.729.g45daf8777d-goog


^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v6 2/4] arm64: dts: mt8183: Add node for the Mali GPU
  2021-01-05  0:11 [PATCH v6 0/4] drm/panfrost: Add support for mt8183 GPU Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 1/4] dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183 Nicolas Boichat
@ 2021-01-05  0:11 ` Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1 Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 4/4] drm/panfrost: Add mt8183-mali compatible string Nicolas Boichat
  3 siblings, 0 replies; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-05  0:11 UTC (permalink / raw)
  To: Rob Herring, Steven Price, Alyssa Rosenzweig
  Cc: hsinyi, hoegsberg, fshao, boris.brezillon, Nicolas Boichat,
	Matthias Brugger, Rob Herring, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek

Add a basic GPU node for mt8183.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
---
The binding we use with out-of-tree Mali drivers includes more
clocks, this is used for devfreq: the out-of-tree driver switches
clk_mux to clk_sub_parent (26Mhz), adjusts clk_main_parent, then
switches clk_mux back to clk_main_parent:
(see https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.19/drivers/gpu/arm/midgard/platform/mediatek/mali_kbase_runtime_pm.c#423)
clocks =
        <&topckgen CLK_TOP_MFGPLL_CK>,
        <&topckgen CLK_TOP_MUX_MFG>,
        <&clk26m>,
        <&mfgcfg CLK_MFG_BG3D>;
clock-names =
        "clk_main_parent",
        "clk_mux",
        "clk_sub_parent",
        "subsys_mfg_cg";
(based on discussions, this probably belongs in the clock core)

This only matters for devfreq, that is disabled anyway as we don't
have platform-specific code to handle >1 supplies.

Changes in v6:
 - Add gpu regulators to kukui dtsi as well.
 - Power domains are now attached to spm, not scpsys
 - Drop R-B.

Changes in v5:
 - Rename "2d" power domain to "core2" (keep R-B again).

Changes in v4:
 - Add power-domain-names to describe the 3 domains.
   (kept Alyssa's reviewed-by as the change is minor)

Changes in v3:
 - No changes

Changes in v2:
 - Use sram instead of mali_sram as SRAM supply name.
 - Rename mali@ to gpu@.

 arch/arm64/boot/dts/mediatek/mt8183-evb.dts   |   6 +
 .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi |   6 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      | 105 ++++++++++++++++++
 3 files changed, 117 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8183-evb.dts b/arch/arm64/boot/dts/mediatek/mt8183-evb.dts
index cba2d8933e79..0a8c2fad8e16 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183-evb.dts
+++ b/arch/arm64/boot/dts/mediatek/mt8183-evb.dts
@@ -42,6 +42,12 @@ &auxadc {
 	status = "okay";
 };
 
+&gpu {
+	supply-names = "mali", "sram";
+	mali-supply = <&mt6358_vgpu_reg>;
+	sram-supply = <&mt6358_vsram_gpu_reg>;
+};
+
 &i2c0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&i2c_pins_0>;
diff --git a/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi b/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi
index bf2ad1294dd3..00d8e112cab9 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi
@@ -249,6 +249,12 @@ &cpu7 {
 	proc-supply = <&mt6358_vproc11_reg>;
 };
 
+&gpu {
+	supply-names = "mali", "sram";
+	mali-supply = <&mt6358_vgpu_reg>;
+	sram-supply = <&mt6358_vsram_gpu_reg>;
+};
+
 &i2c0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&i2c0_pins>;
diff --git a/arch/arm64/boot/dts/mediatek/mt8183.dtsi b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
index 5b782a4769e7..5430e05e18a0 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
@@ -964,6 +964,111 @@ mfgcfg: syscon@13000000 {
 			#clock-cells = <1>;
 		};
 
+		gpu: gpu@13040000 {
+			compatible = "mediatek,mt8183-mali", "arm,mali-bifrost";
+			reg = <0 0x13040000 0 0x4000>;
+			interrupts =
+				<GIC_SPI 280 IRQ_TYPE_LEVEL_LOW>,
+				<GIC_SPI 279 IRQ_TYPE_LEVEL_LOW>,
+				<GIC_SPI 278 IRQ_TYPE_LEVEL_LOW>;
+			interrupt-names = "job", "mmu", "gpu";
+
+			clocks = <&topckgen CLK_TOP_MFGPLL_CK>;
+
+			power-domains =
+				<&spm MT8183_POWER_DOMAIN_MFG_CORE0>,
+				<&spm MT8183_POWER_DOMAIN_MFG_CORE1>,
+				<&spm MT8183_POWER_DOMAIN_MFG_2D>;
+			power-domain-names = "core0", "core1", "core2";
+
+			operating-points-v2 = <&gpu_opp_table>;
+		};
+
+		gpu_opp_table: opp_table0 {
+			compatible = "operating-points-v2";
+			opp-shared;
+
+			opp-300000000 {
+				opp-hz = /bits/ 64 <300000000>;
+				opp-microvolt = <625000>, <850000>;
+			};
+
+			opp-320000000 {
+				opp-hz = /bits/ 64 <320000000>;
+				opp-microvolt = <631250>, <850000>;
+			};
+
+			opp-340000000 {
+				opp-hz = /bits/ 64 <340000000>;
+				opp-microvolt = <637500>, <850000>;
+			};
+
+			opp-360000000 {
+				opp-hz = /bits/ 64 <360000000>;
+				opp-microvolt = <643750>, <850000>;
+			};
+
+			opp-380000000 {
+				opp-hz = /bits/ 64 <380000000>;
+				opp-microvolt = <650000>, <850000>;
+			};
+
+			opp-400000000 {
+				opp-hz = /bits/ 64 <400000000>;
+				opp-microvolt = <656250>, <850000>;
+			};
+
+			opp-420000000 {
+				opp-hz = /bits/ 64 <420000000>;
+				opp-microvolt = <662500>, <850000>;
+			};
+
+			opp-460000000 {
+				opp-hz = /bits/ 64 <460000000>;
+				opp-microvolt = <675000>, <850000>;
+			};
+
+			opp-500000000 {
+				opp-hz = /bits/ 64 <500000000>;
+				opp-microvolt = <687500>, <850000>;
+			};
+
+			opp-540000000 {
+				opp-hz = /bits/ 64 <540000000>;
+				opp-microvolt = <700000>, <850000>;
+			};
+
+			opp-580000000 {
+				opp-hz = /bits/ 64 <580000000>;
+				opp-microvolt = <712500>, <850000>;
+			};
+
+			opp-620000000 {
+				opp-hz = /bits/ 64 <620000000>;
+				opp-microvolt = <725000>, <850000>;
+			};
+
+			opp-653000000 {
+				opp-hz = /bits/ 64 <653000000>;
+				opp-microvolt = <743750>, <850000>;
+			};
+
+			opp-698000000 {
+				opp-hz = /bits/ 64 <698000000>;
+				opp-microvolt = <768750>, <868750>;
+			};
+
+			opp-743000000 {
+				opp-hz = /bits/ 64 <743000000>;
+				opp-microvolt = <793750>, <893750>;
+			};
+
+			opp-800000000 {
+				opp-hz = /bits/ 64 <800000000>;
+				opp-microvolt = <825000>, <925000>;
+			};
+		};
+
 		mmsys: syscon@14000000 {
 			compatible = "mediatek,mt8183-mmsys", "syscon";
 			reg = <0 0x14000000 0 0x1000>;
-- 
2.29.2.729.g45daf8777d-goog


^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
  2021-01-05  0:11 [PATCH v6 0/4] drm/panfrost: Add support for mt8183 GPU Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 1/4] dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183 Nicolas Boichat
  2021-01-05  0:11 ` [PATCH v6 2/4] arm64: dts: mt8183: Add node for the Mali GPU Nicolas Boichat
@ 2021-01-05  0:11 ` Nicolas Boichat
  2021-01-05  0:34   ` Alyssa Rosenzweig
  2021-01-07 15:59   ` Steven Price
  2021-01-05  0:11 ` [PATCH v6 4/4] drm/panfrost: Add mt8183-mali compatible string Nicolas Boichat
  3 siblings, 2 replies; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-05  0:11 UTC (permalink / raw)
  To: Rob Herring, Steven Price, Alyssa Rosenzweig
  Cc: hsinyi, hoegsberg, fshao, boris.brezillon, Nicolas Boichat,
	Daniel Vetter, David Airlie, Tomeu Vizoso, dri-devel,
	linux-kernel

GPUs with more than a single regulator (e.g. G-57 on MT8183) will
require platform-specific handling, disable devfreq for now.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
---

Changes in v6:
 - New change

 drivers/gpu/drm/panfrost/panfrost_devfreq.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
index f44d28fad085..1f49043aae73 100644
--- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
+++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
@@ -92,6 +92,15 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
 	struct thermal_cooling_device *cooling;
 	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
 
+	if (pfdev->comp->num_supplies > 1) {
+		/*
+		 * GPUs with more than 1 supply require platform-specific handling:
+		 * continue without devfreq
+		 */
+		DRM_DEV_ERROR(dev, "More than 1 supply is not supported yet\n");
+		return 0;
+	}
+
 	opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
 					      pfdev->comp->num_supplies);
 	if (IS_ERR(opp_table)) {
-- 
2.29.2.729.g45daf8777d-goog


^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v6 4/4] drm/panfrost: Add mt8183-mali compatible string
  2021-01-05  0:11 [PATCH v6 0/4] drm/panfrost: Add support for mt8183 GPU Nicolas Boichat
                   ` (2 preceding siblings ...)
  2021-01-05  0:11 ` [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1 Nicolas Boichat
@ 2021-01-05  0:11 ` Nicolas Boichat
  2021-01-05  0:35   ` Alyssa Rosenzweig
  3 siblings, 1 reply; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-05  0:11 UTC (permalink / raw)
  To: Rob Herring, Steven Price, Alyssa Rosenzweig
  Cc: hsinyi, hoegsberg, fshao, boris.brezillon, Nicolas Boichat,
	Daniel Vetter, David Airlie, Matthias Brugger, Tomeu Vizoso,
	dri-devel, linux-arm-kernel, linux-kernel, linux-mediatek

Add support for MT8183's G-57 Bifrost.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
---

Changes in v6:
 - Context conflicts, reflow the code.
 - Use ARRAY_SIZE for power domains too.

Changes in v5:
 - Change power domain name from 2d to core2.

Changes in v4:
 - Add power domain names.

Changes in v3:
 - Match mt8183-mali instead of bifrost, as we require special
   handling for the 2 regulators and 3 power domains.

 drivers/gpu/drm/panfrost/panfrost_drv.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 83a461bdeea8..ca07098a6141 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -665,6 +665,15 @@ static const struct panfrost_compatible amlogic_data = {
 	.vendor_quirk = panfrost_gpu_amlogic_quirk,
 };
 
+const char * const mediatek_mt8183_supplies[] = { "mali", "sram" };
+const char * const mediatek_mt8183_pm_domains[] = { "core0", "core1", "core2" };
+static const struct panfrost_compatible mediatek_mt8183_data = {
+	.num_supplies = ARRAY_SIZE(mediatek_mt8183_supplies),
+	.supply_names = mediatek_mt8183_supplies,
+	.num_pm_domains = ARRAY_SIZE(mediatek_mt8183_pm_domains),
+	.pm_domain_names = mediatek_mt8183_pm_domains,
+};
+
 static const struct of_device_id dt_match[] = {
 	/* Set first to probe before the generic compatibles */
 	{ .compatible = "amlogic,meson-gxm-mali",
@@ -681,6 +690,7 @@ static const struct of_device_id dt_match[] = {
 	{ .compatible = "arm,mali-t860", .data = &default_data, },
 	{ .compatible = "arm,mali-t880", .data = &default_data, },
 	{ .compatible = "arm,mali-bifrost", .data = &default_data, },
+	{ .compatible = "mediatek,mt8183-mali", .data = &mediatek_mt8183_data },
 	{}
 };
 MODULE_DEVICE_TABLE(of, dt_match);
-- 
2.29.2.729.g45daf8777d-goog


^ permalink raw reply related	[flat|nested] 10+ messages in thread

* Re: [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
  2021-01-05  0:11 ` [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1 Nicolas Boichat
@ 2021-01-05  0:34   ` Alyssa Rosenzweig
  2021-01-05  0:59     ` Nicolas Boichat
  2021-01-07 15:59   ` Steven Price
  1 sibling, 1 reply; 10+ messages in thread
From: Alyssa Rosenzweig @ 2021-01-05  0:34 UTC (permalink / raw)
  To: Nicolas Boichat
  Cc: Rob Herring, Steven Price, hsinyi, hoegsberg, fshao,
	boris.brezillon, Daniel Vetter, David Airlie, Tomeu Vizoso,
	dri-devel, linux-kernel

[-- Attachment #1: Type: text/plain, Size: 73 bytes --]

> GPUs with more than a single regulator (e.g. G-57 on MT8183) will

G72

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v6 4/4] drm/panfrost: Add mt8183-mali compatible string
  2021-01-05  0:11 ` [PATCH v6 4/4] drm/panfrost: Add mt8183-mali compatible string Nicolas Boichat
@ 2021-01-05  0:35   ` Alyssa Rosenzweig
  0 siblings, 0 replies; 10+ messages in thread
From: Alyssa Rosenzweig @ 2021-01-05  0:35 UTC (permalink / raw)
  To: Nicolas Boichat
  Cc: Rob Herring, Steven Price, hsinyi, hoegsberg, fshao,
	boris.brezillon, Daniel Vetter, David Airlie, Matthias Brugger,
	Tomeu Vizoso, dri-devel, linux-arm-kernel, linux-kernel,
	linux-mediatek

[-- Attachment #1: Type: text/plain, Size: 46 bytes --]

> Add support for MT8183's G-57 Bifrost.

G72

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
  2021-01-05  0:34   ` Alyssa Rosenzweig
@ 2021-01-05  0:59     ` Nicolas Boichat
  0 siblings, 0 replies; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-05  0:59 UTC (permalink / raw)
  To: Alyssa Rosenzweig
  Cc: Rob Herring, Steven Price, Hsin-Yi Wang, hoegsberg, Fei Shao,
	Boris Brezillon, Daniel Vetter, David Airlie, Tomeu Vizoso,
	dri-devel, lkml

On Tue, Jan 5, 2021 at 8:34 AM Alyssa Rosenzweig
<alyssa.rosenzweig@collabora.com> wrote:
>
> > GPUs with more than a single regulator (e.g. G-57 on MT8183) will
>
> G72

Duh, sorry, yes. I will fix that in v7.

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
  2021-01-05  0:11 ` [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1 Nicolas Boichat
  2021-01-05  0:34   ` Alyssa Rosenzweig
@ 2021-01-07 15:59   ` Steven Price
  2021-01-07 23:51     ` Nicolas Boichat
  1 sibling, 1 reply; 10+ messages in thread
From: Steven Price @ 2021-01-07 15:59 UTC (permalink / raw)
  To: Nicolas Boichat, Rob Herring, Alyssa Rosenzweig
  Cc: hsinyi, hoegsberg, fshao, boris.brezillon, Daniel Vetter,
	David Airlie, Tomeu Vizoso, dri-devel, linux-kernel

On 05/01/2021 00:11, Nicolas Boichat wrote:
> GPUs with more than a single regulator (e.g. G-57 on MT8183) will
> require platform-specific handling, disable devfreq for now.

Can you explain what actually goes wrong here? AFAICT the existing code 
does support controlling multiple regulators - but clearly this is the 
first platform that exercises that code with num_supplies>1.

Steve

> 
> Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> ---
> 
> Changes in v6:
>   - New change
> 
>   drivers/gpu/drm/panfrost/panfrost_devfreq.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index f44d28fad085..1f49043aae73 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -92,6 +92,15 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>   	struct thermal_cooling_device *cooling;
>   	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
>   
> +	if (pfdev->comp->num_supplies > 1) {
> +		/*
> +		 * GPUs with more than 1 supply require platform-specific handling:
> +		 * continue without devfreq
> +		 */
> +		DRM_DEV_ERROR(dev, "More than 1 supply is not supported yet\n");
> +		return 0;
> +	}
> +
>   	opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
>   					      pfdev->comp->num_supplies);
>   	if (IS_ERR(opp_table)) {
> 


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
  2021-01-07 15:59   ` Steven Price
@ 2021-01-07 23:51     ` Nicolas Boichat
  0 siblings, 0 replies; 10+ messages in thread
From: Nicolas Boichat @ 2021-01-07 23:51 UTC (permalink / raw)
  To: Steven Price
  Cc: Rob Herring, Alyssa Rosenzweig, Hsin-Yi Wang,
	Kristian Kristensen, Fei Shao, Boris Brezillon, Daniel Vetter,
	David Airlie, Tomeu Vizoso, dri-devel, lkml

On Thu, Jan 7, 2021 at 11:59 PM Steven Price <steven.price@arm.com> wrote:
>
> On 05/01/2021 00:11, Nicolas Boichat wrote:
> > GPUs with more than a single regulator (e.g. G-57 on MT8183) will
> > require platform-specific handling, disable devfreq for now.
>
> Can you explain what actually goes wrong here? AFAICT the existing code
> does support controlling multiple regulators - but clearly this is the
> first platform that exercises that code with num_supplies>1.

Sure, I should have expanded in the commit message, will do in v9.

We have support for >1 supplies, and we need to enable them to get the
GPU running _at all_ (and the default voltages should be safe by
design).

For devfreq though:
 1. There are constraints on the voltage difference between the core
and SRAM, we have this caterpillar logic downstream [1], so somebody
will need to port it (TBH I don't think it's overly critical at this
point, as Bifrost support is still not very mature from what I can
see, and devfreq is purely a performance thing).
 2. The core [2] does not support multiple regulators, so we'll need
custom code anyway. Even if we didn't have constraints.

[1] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/refs/heads/chromeos-4.19/drivers/gpu/arm/bifrost/platform/mediatek/mali_kbase_runtime_pm.c#367
[2] https://elixir.bootlin.com/linux/latest/source/drivers/opp/core.c#L679

>
> Steve
>
> >
> > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> > ---
> >
> > Changes in v6:
> >   - New change
> >
> >   drivers/gpu/drm/panfrost/panfrost_devfreq.c | 9 +++++++++
> >   1 file changed, 9 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > index f44d28fad085..1f49043aae73 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > @@ -92,6 +92,15 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
> >       struct thermal_cooling_device *cooling;
> >       struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
> >
> > +     if (pfdev->comp->num_supplies > 1) {
> > +             /*
> > +              * GPUs with more than 1 supply require platform-specific handling:
> > +              * continue without devfreq
> > +              */
> > +             DRM_DEV_ERROR(dev, "More than 1 supply is not supported yet\n");
> > +             return 0;
> > +     }
> > +
> >       opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
> >                                             pfdev->comp->num_supplies);
> >       if (IS_ERR(opp_table)) {
> >
>

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2021-01-07 23:52 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-05  0:11 [PATCH v6 0/4] drm/panfrost: Add support for mt8183 GPU Nicolas Boichat
2021-01-05  0:11 ` [PATCH v6 1/4] dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183 Nicolas Boichat
2021-01-05  0:11 ` [PATCH v6 2/4] arm64: dts: mt8183: Add node for the Mali GPU Nicolas Boichat
2021-01-05  0:11 ` [PATCH v6 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1 Nicolas Boichat
2021-01-05  0:34   ` Alyssa Rosenzweig
2021-01-05  0:59     ` Nicolas Boichat
2021-01-07 15:59   ` Steven Price
2021-01-07 23:51     ` Nicolas Boichat
2021-01-05  0:11 ` [PATCH v6 4/4] drm/panfrost: Add mt8183-mali compatible string Nicolas Boichat
2021-01-05  0:35   ` Alyssa Rosenzweig

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).