From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE2A3606A323 for ; Fri, 23 Oct 2026 14:32:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=BL/Lw7tc Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2AF0810E63B; Fri, 23 Oct 2026 14:32:48 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id B503E10E496 for ; Fri, 23 Oct 2026 14:32:23 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 129C91C14 for ; Fri, 23 Oct 2026 07:32:20 -0700 (PDT) Received: from [192.168.0.1] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 102113F673 for ; Fri, 23 Oct 2026 07:32:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1792765943; bh=anSElN5yBjJkYZBOkU/8sr3NncGEwgUdXZ2Ow2+bIdw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BL/Lw7tclapUr7xayI4e5tm8BlgTgxOue8eA9KsEck5zw3e6OQRm4gE14NwORC/VC 9BzeB0cmSAlgD+t80YURutxCaoC1cDUBvaVHlcfK699RDsi3X+VGZdPGcVbtoZH4m4 WrkZiMlCp3BoSRe9eqMhncM+KVAGp041YJAiUMB4= Date: Fri, 23 Oct 2026 15:32:11 +0100 From: Liviu Dudau To: Lukas Zapolskas Cc: Daniel Almeida , Alice Ryhl , Boris Brezillon , Steven Price , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, nd@arm.com Subject: Re: [PATCH v7 7/8] drm/panthor: Add suspend, resume and reset handling Message-ID: References: <20261011-panthor-performance-counters-v7-0-12c32495062f@arm.com> <20261011-panthor-performance-counters-v7-7-12c32495062f@arm.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20261011-panthor-performance-counters-v7-7-12c32495062f@arm.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "dri-devel" X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Minor nit: subject line gives the wrong idea about the patch. On Sun, Oct 11, 2026 at 06:36:54PM +0100, Lukas Zapolskas wrote: > The sampler must disable and re-enable counter sampling around > suspends, and must re-program the FW interface after a reset to > avoid losing data. Additionally, if a request was pending before the > reset and it was not acked, the reset will have cleared it, so we toggle > the flag and re-request a sample. > > Signed-off-by: Lukas Zapolskas > --- > drivers/gpu/drm/panthor/panthor_device.c | 8 ++- > drivers/gpu/drm/panthor/panthor_perf.c | 83 ++++++++++++++++++++++++++++++++ > drivers/gpu/drm/panthor/panthor_perf.h | 6 +++ > 3 files changed, 96 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c > index 535383ef629f..c842480472ac 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.c > +++ b/drivers/gpu/drm/panthor/panthor_device.c > @@ -138,6 +138,7 @@ static void panthor_device_reset_work(struct work_struct *work) > if (!drm_dev_enter(&ptdev->base, &cookie)) > return; > > + panthor_perf_pre_reset(ptdev); > panthor_sched_pre_reset(ptdev); > panthor_fw_pre_reset(ptdev, true); > panthor_mmu_pre_reset(ptdev); > @@ -147,6 +148,8 @@ static void panthor_device_reset_work(struct work_struct *work) > ret = panthor_fw_post_reset(ptdev); > atomic_set(&ptdev->reset.pending, 0); > panthor_sched_post_reset(ptdev, ret != 0); > + if (!ret) > + panthor_perf_post_reset(ptdev); > drm_dev_exit(cookie); > > if (ret) { > @@ -539,8 +542,10 @@ int panthor_device_resume(struct device *dev) > ret = panthor_device_resume_hw_components(ptdev); > } > > - if (!ret) > + if (!ret) { > panthor_sched_resume(ptdev); > + panthor_perf_resume(ptdev); > + } > > drm_dev_exit(cookie); > > @@ -604,6 +609,7 @@ int panthor_device_suspend(struct device *dev) > /* We prepare everything as if we were resetting the GPU. > * The end of the reset will happen in the resume path though. > */ > + panthor_perf_suspend(ptdev); > panthor_sched_suspend(ptdev); > panthor_fw_suspend(ptdev); > panthor_mmu_suspend(ptdev); > diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c > index c66ad658a95d..28b02003f9f9 100644 > --- a/drivers/gpu/drm/panthor/panthor_perf.c > +++ b/drivers/gpu/drm/panthor/panthor_perf.c > @@ -1798,6 +1798,57 @@ int panthor_perf_session_sample(struct panthor_file *pfile, u32 handle, u64 user > return err; > } > > +/** > + * panthor_perf_suspend - Prepare the performance counter subsystem for system suspend. > + * @ptdev: Panthor device. > + * > + * Indicate to the performance counters that the system is suspending. > + * > + * This function must not be used to handle MCU power state transitions: just before MCU goes > + * from on to any inactive state, an automatic sample will be performed by the firmware, and > + * the performance counter firmware state will be restored on warm boot. > + * > + */ > +void panthor_perf_suspend(struct panthor_device *ptdev) > +{ > + struct panthor_perf *perf = ptdev->perf; > + int ret; > + > + if (!perf) > + return; > + > + guard(mutex)(&perf->op_lock); > + > + ret = perf_disable(perf); > + > + if (ret) > + drm_warn(&ptdev->base, "Could not stop sampling before suspend, err = %d", ret); > +} > + > +/** > + * panthor_perf_resume - Resume the performance counter subsystem after system resumption. > + * @ptdev: Panthor device. > + * > + * Indicate to the performance counters that the system has resumed. This must not be used > + * to handle MCU state transitions, for the same reasons as detailed in the kerneldoc for > + * @panthor_perf_suspend. > + */ > +void panthor_perf_resume(struct panthor_device *ptdev) > +{ > + struct panthor_perf *perf = ptdev->perf; > + int ret; > + > + if (!perf) > + return; > + > + guard(mutex)(&perf->op_lock); > + > + ret = perf_enable(perf); > + > + if (ret) > + drm_warn(&ptdev->base, "Could not resume sampling, err = %d", ret); > +} > + > /** > * panthor_perf_unplug - Terminate the performance counter subsystem. > * @ptdev: Panthor device. > @@ -1868,3 +1919,35 @@ void panthor_perf_pool_destroy(struct panthor_file *pfile) > > pfile->sessions = NULL; > } > + > +void panthor_perf_pre_reset(struct panthor_device *ptdev) > +{ > + if (!ptdev->perf) > + return; > + > + guard(mutex)(&ptdev->perf->op_lock); > + > + perf_disable(ptdev->perf); > +} > + > +void panthor_perf_post_reset(struct panthor_device *ptdev) > +{ > + bool rerequest = false; > + > + if (!ptdev->perf) > + return; > + > + guard(mutex)(&ptdev->perf->op_lock); > + > + perf_enable(ptdev->perf); > + > + scoped_guard(spinlock_irqsave, &ptdev->perf->pend_lock) { > + rerequest = ptdev->perf->fw_sample_requested; > + > + if (rerequest) > + ptdev->perf->fw_sample_requested = false; > + } > + > + if (rerequest) > + perf_fw_request_sample(ptdev->perf); > +} > diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h > index 0e1172dbae39..e4a323fe6f0d 100644 > --- a/drivers/gpu/drm/panthor/panthor_perf.h > +++ b/drivers/gpu/drm/panthor/panthor_perf.h > @@ -18,6 +18,8 @@ int panthor_perf_pool_create(struct panthor_file *pfile); > void panthor_perf_pool_destroy(struct panthor_file *pfile); > > int panthor_perf_init(struct panthor_device *ptdev); > +void panthor_perf_suspend(struct panthor_device *ptdev); > +void panthor_perf_resume(struct panthor_device *ptdev); > void panthor_perf_unplug(struct panthor_device *ptdev); > > int panthor_perf_session_create(struct drm_file *file, > @@ -30,5 +32,9 @@ int panthor_perf_session_sample(struct panthor_file *pfile, unsigned int handle, > > void panthor_perf_report_irq(struct panthor_device *ptdev, u32 status); > > +void panthor_perf_pre_reset(struct panthor_device *ptdev); > + > +void panthor_perf_post_reset(struct panthor_device *ptdev); > + > #endif /* __PANTHOR_PERF_H__ */ > > > -- > 2.43.0 > Reviewed-by: Liviu Dudau Best regards, Liviu -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯