From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5BC041D5ADE for ; Thu, 9 Oct 2025 15:17:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760023052; cv=none; b=CnZLgNO7JU7nNwwrzBt2gy6nS42fHNEvDiDA6tlnT/KJD7Z9rBJFey1nsnp0V88iQXgQVbPQaiIEMSDtDtfZ4bigaVD4xgvjeqBRrfbdRmqHM75ivm3hjcyA1Kda+Cg0iG2gZDksleDPkrfkR1PetJjmSBBy2OHBBQRPlkPjKtE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760023052; c=relaxed/simple; bh=5jqOKuKfhFoLEaWgi9thITVIR3ykMo/O+lz9T2klnQ8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=o/jkLceyufTGAOZDRfAHTaXv93GyAYwd5fKQWhKW+83A2DJUjsdhh0yp1W16vFPfEW4kz0MRScnuzyE2fxAAM64y0hXQaa5aJV5MSdMFTqv3IXFlvx1bZyxfPju0Ip3D6leq3kBu9Q/ChWKy8R49eLhP81tbhK9uefGO27oxsKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 652601A2D; Thu, 9 Oct 2025 08:17:22 -0700 (PDT) Received: from [10.1.34.29] (e122027.cambridge.arm.com [10.1.34.29]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E42CE3F59E; Thu, 9 Oct 2025 08:17:27 -0700 (PDT) Message-ID: Date: Thu, 9 Oct 2025 16:17:22 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 04/12] drm/panfrost: Handle error when allocating AS number To: =?UTF-8?Q?Adri=C3=A1n_Larumbe?= , linux-kernel@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, Boris Brezillon , kernel@collabora.com, Rob Herring , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter References: <20251007150216.254250-1-adrian.larumbe@collabora.com> <20251007150216.254250-5-adrian.larumbe@collabora.com> From: Steven Price Content-Language: en-GB In-Reply-To: <20251007150216.254250-5-adrian.larumbe@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 07/10/2025 16:01, Adrián Larumbe wrote: > If we reach the beginning of the LRU AS list, then return an error. > > Reviewed-by: Boris Brezillon > Signed-off-by: Adrián Larumbe Very much "should never happen", but I guess adding error handling can't hurt ;) One minor NIT below, but either way: Reviewed-by: Steven Price > --- > drivers/gpu/drm/panfrost/panfrost_job.c | 6 +++++- > drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 +++-- > drivers/gpu/drm/panfrost/panfrost_mmu.h | 2 +- > drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 9 ++++++++- > 4 files changed, 17 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c > index ea3f2878fd15..1b3af5d52081 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_job.c > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > @@ -213,7 +213,11 @@ static int panfrost_job_hw_submit(struct panfrost_job *job, int js) > goto err_hwsubmit; > } > > - cfg = panfrost_mmu_as_get(pfdev, job->mmu); > + ret = panfrost_mmu_as_get(pfdev, job->mmu); > + if (ret < 0) > + goto err_hwsubmit; > + > + cfg = ret; > > panfrost_devfreq_record_busy(&pfdev->pfdevfreq); > > diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c > index 1d696eeea2fa..cf272b167feb 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c > +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c > @@ -258,7 +258,7 @@ static int panfrost_mmu_cfg_init(struct panfrost_mmu *mmu, > } > } > > -u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu) > +int panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu) > { > int as; > > @@ -300,7 +300,8 @@ u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu) > if (!atomic_read(&lru_mmu->as_count)) > break; > } > - WARN_ON(&lru_mmu->list == &pfdev->as_lru_list); > + if (WARN_ON(&lru_mmu->list == &pfdev->as_lru_list)) > + return -EBUSY; > > list_del_init(&lru_mmu->list); > as = lru_mmu->as; > diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.h b/drivers/gpu/drm/panfrost/panfrost_mmu.h > index 022a9a74a114..e6e6966a0cca 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_mmu.h > +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.h > @@ -16,7 +16,7 @@ void panfrost_mmu_fini(struct panfrost_device *pfdev); > void panfrost_mmu_reset(struct panfrost_device *pfdev); > void panfrost_mmu_suspend_irq(struct panfrost_device *pfdev); > > -u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu); > +int panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu); > void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu); > > struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu); > diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > index 718eb44b40f8..a8d821e1bde2 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > @@ -132,7 +132,12 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev, > > perfcnt->user = user; NIT: If we just move this line below the call to panfrost_mmu_as_get() then we don't need the extra label and the special error handling. Thanks, Steve > > - as = panfrost_mmu_as_get(pfdev, perfcnt->mapping->mmu); > + ret = panfrost_mmu_as_get(pfdev, perfcnt->mapping->mmu); > + if (ret < 0) > + goto err_unsetuser; > + > + as = ret; > + > cfg = GPU_PERFCNT_CFG_AS(as) | > GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_MANUAL); > > @@ -166,6 +171,8 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev, > > return 0; > > +err_unsetuser: > + perfcnt->user = NULL; > err_vunmap: > drm_gem_vunmap(&bo->base, &map); > err_put_mapping: