linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Nicolas Boichat <drinkcat@chromium.org>
To: Rob Herring <robh@kernel.org>,
	Steven Price <steven.price@arm.com>,
	Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: fshao@chromium.org, hsinyi@chromium.org, hoegsberg@chromium.org,
	Tomeu Vizoso <tomeu.vizoso@collabora.com>,
	Neil Armstrong <narmstrong@baylibre.com>,
	boris.brezillon@collabora.com,
	Nicolas Boichat <drinkcat@chromium.org>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH v13 3/4] drm/panfrost: devfreq: Disable devfreq when num_supplies > 1
Date: Wed, 21 Apr 2021 13:28:54 +0800	[thread overview]
Message-ID: <20210421132841.v13.3.I3af068abe30c9c85cabc4486385c52e56527a509@changeid> (raw)
In-Reply-To: <20210421052855.1279713-1-drinkcat@chromium.org>

GPUs with more than a single regulator (e.g. G72 on MT8183) will
require platform-specific handling for devfreq, for 2 reasons:
 1. The opp core (drivers/opp/core.c:_generic_set_opp_regulator)
    does not support multiple regulators, so we'll need custom
    handlers.
 2. Generally, platforms with 2 regulators have platform-specific
    constraints on how the voltages should be set (e.g.
    minimum/maximum voltage difference between them), so we
    should not just create generic handlers that simply
    change the voltages without taking care of those constraints.

Disable devfreq for now on those GPUs.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
---

Changes in v13:
 - devfreq: Fix conflict resolution mistake when rebasing, didn't
   even compile. Oops.

Changes in v9:
 - Explain why devfreq needs to be disabled for GPUs with >1
   regulators.

Changes in v8:
 - Use DRM_DEV_INFO instead of ERROR

Changes in v7:
 - Fix GPU ID in commit message

Changes in v6:
 - devfreq: 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 47d27e54a34f..3644652f726f 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_INFO(dev, "More than 1 supply is not supported yet\n");
+		return 0;
+	}
+
 	ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
 					 pfdev->comp->num_supplies);
 	if (ret) {
-- 
2.31.1.368.gbe11c130af-goog


  parent reply	other threads:[~2021-04-21  5:29 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-21  5:28 [PATCH v13 0/4] drm/panfrost: Add support for mt8183 GPU Nicolas Boichat
2021-04-21  5:28 ` [PATCH v13 1/4] dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183 Nicolas Boichat
2021-04-21 16:59   ` Rob Herring
2021-04-21  5:28 ` [PATCH v13 2/4] arm64: dts: mt8183: Add node for the Mali GPU Nicolas Boichat
2021-05-13 14:51   ` Ezequiel Garcia
2021-04-21  5:28 ` Nicolas Boichat [this message]
2021-04-21  5:28 ` [PATCH v13 4/4] drm/panfrost: Add mt8183-mali compatible string Nicolas Boichat
2021-04-21 13:17   ` Alyssa Rosenzweig
2021-04-26  9:58 ` [PATCH v13 0/4] drm/panfrost: Add support for mt8183 GPU Neil Armstrong
2021-05-13 14:55   ` Ezequiel Garcia
2021-05-14 14:48     ` Neil Armstrong
2021-05-14 15:27       ` Steven Price
2021-05-15  1:29         ` Nicolas Boichat
2021-05-17 10:24         ` Neil Armstrong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210421132841.v13.3.I3af068abe30c9c85cabc4486385c52e56527a509@changeid \
    --to=drinkcat@chromium.org \
    --cc=airlied@linux.ie \
    --cc=alyssa.rosenzweig@collabora.com \
    --cc=boris.brezillon@collabora.com \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=fshao@chromium.org \
    --cc=hoegsberg@chromium.org \
    --cc=hsinyi@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=narmstrong@baylibre.com \
    --cc=robh@kernel.org \
    --cc=steven.price@arm.com \
    --cc=tomeu.vizoso@collabora.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).