From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C079E147C9B for ; Mon, 14 Oct 2024 07:29:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728890943; cv=none; b=p6e4b2ruA0E2o5d+/a30mFZD2LFhR0nJVUAZSJX1YZBn0xzqAnNiX8euAbCxAsmjivFYXQBCtiK3Tw1LCx700F401tqTZs2o4pISvrFJOLPUgXzA3v/H3Ic9etnHJjhWxeCYEcQ6nn/IPtosGSK5XdknLP1f57EYmzWDmyyQ8F0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728890943; c=relaxed/simple; bh=PluJBjCt8sRWlyCdfJRAdmc/ItMwAA9IVKhhVYczlKA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=cZtQ8iaVjlAASwFFVg5LBzlER/Ka4L6Y4CzvxgKPlDbxea6P94F2em8jAuX+OJbz02KcvuAI0v/ZC7jM0062FBJ91WgKejqYO8LfNV94Ukd/Or7VyAsocvf7ZoyICMRW6SMsfDn6JxdOfKkptuOrH27YREm/ZK4iiz+uQUkrotY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=LDbI7pvw; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="LDbI7pvw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1728890939; bh=PluJBjCt8sRWlyCdfJRAdmc/ItMwAA9IVKhhVYczlKA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LDbI7pvwQLh2IrwJa7JQJLtLnKpxHnIJrTtDW8TV4hcNRQFOiIe5JLAt4bl8o4w2g DoMpeRjZXFyWImlH+YgWdT9c7NKdB/4o97IIGNqPcmcTGcHOtQoOhZUnWuiEvgBSJZ zqxEBuqwuUkxViNddVr+ywW6ic5Hf+qU8bpWu9vYqiWFJLlcLtDEAcA09wjFVb42Se 26Qv04tX64kneCp4TXneEtrnpG3QGcrTW8WYT775c0wqXhJrzy9YjDGOIBKh290z44 S2eNzxGhNlFGnvZHg8wCpMKNjJahwzGdhPHnhzvcNWpddnS+zzdGdc2T3hOg6QCtQI vWIB9SMFJ1qQw== Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 7C04B17E10AA; Mon, 14 Oct 2024 09:28:59 +0200 (CEST) Date: Mon, 14 Oct 2024 09:28:55 +0200 From: Boris Brezillon To: =?UTF-8?B?QWRyacOhbg==?= Larumbe Cc: Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] drm/panthor: Retry OPP transition to suspension state a few times Message-ID: <20241014092855.5c761b13@collabora.com> In-Reply-To: <20241011225906.3789965-2-adrian.larumbe@collabora.com> References: <20241011225906.3789965-1-adrian.larumbe@collabora.com> <20241011225906.3789965-2-adrian.larumbe@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Fri, 11 Oct 2024 23:57:00 +0100 Adri=C3=A1n Larumbe wrote: > When the device's runtime PM suspend callback is invoked, the switch to > a suspension OPP might sometimes fail. Although this is beyond the > control of the Panthor driver, we can attempt suspending it more than > once as a defensive strategy. >=20 > Signed-off-by: Adri=C3=A1n Larumbe > --- > drivers/gpu/drm/panthor/panthor_device.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/p= anthor/panthor_device.c > index cedd3cbcb47d..5430557bd0b8 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.c > +++ b/drivers/gpu/drm/panthor/panthor_device.c > @@ -490,6 +490,7 @@ int panthor_device_resume(struct device *dev) > int panthor_device_suspend(struct device *dev) > { > struct panthor_device *ptdev =3D dev_get_drvdata(dev); > + unsigned int susp_retries; > int ret, cookie; > =20 > if (atomic_read(&ptdev->pm.state) !=3D PANTHOR_DEVICE_PM_STATE_ACTIVE) > @@ -522,7 +523,12 @@ int panthor_device_suspend(struct device *dev) > drm_dev_exit(cookie); > } > =20 > - ret =3D panthor_devfreq_suspend(ptdev); > + for (susp_retries =3D 0; susp_retries < 5; susp_retries++) { > + ret =3D panthor_devfreq_suspend(ptdev); > + if (!ret) > + break; > + } This retry logic should probably be moved to panthor_devfreq_suspend(), but as Liviu said, I think we need to better understand why it takes several attempts for an OPP transition to succeed. > + > if (ret) { > if (panthor_device_is_initialized(ptdev) && > drm_dev_enter(&ptdev->base, &cookie)) {