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From: Jon Hunter Message-ID: <315241b5-f5a2-aaa0-7327-24055ff306c7@nvidia.com> Date: Fri, 31 Jan 2020 09:02:28 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1580461332; bh=Nk8oL5vCVqBnXjso+RrvQFAoO6KnCVKaJeZz6xzsl/8=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=qwbWlB+gnELGMmzJ3pe37/TS2E+2LuhUkCNcL2NaqwxRWPmyf0QOxcCDraC4TSeph 2OwXztiZS6lHCux/v7HxJml83AnYTVuRtM8iwSs20T8IttrgRmOadQ3yolR8JrncQW Nl6bEub3LzAAdS5zTBgW+F+YF1Nf4HUHZ4ai4JXCaREK6gvA0nqZGp0itxIKNuPkn/ Fv89ucRjsykm+QCN/WyuUtv6i6jnq82zNI9qER0NvVauq/ycUrterl4c5/OckFzbwB Bl33XCYMzOHkkjeseXmMqimSW0RATB3T40SVn4o7QrriUpQlIlOTiI0khQaMwBmFNz ceIBhl8RhUEbQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/01/2020 20:04, Dmitry Osipenko wrote: ... >>> The tegra_dma_stop() should put RPM anyways, which is missed in yours >>> sample. Please see handle_continuous_head_request(). >> >> Yes and that is deliberate. The cyclic transfers the transfers *should* >> not stop until terminate_all is called. The tegra_dma_stop in >> handle_continuous_head_request() is an error condition and so I am not >> sure it is actually necessary to call pm_runtime_put() here. > > But then tegra_dma_stop() shouldn't unset the "busy" mark. True. >>> I'm also finding the explicit get/put a bit easier to follow in the >>> code, don't you think so? >> >> I can see that, but I was thinking that in the case of cyclic transfers, >> it should only really be necessary to call the get/put at the beginning >> and end. So in my mind there should only be two exit points which are >> the ISR handler for SG and terminate_all for SG and cyclic. > > Alright, I'll update this patch. Hmmm ... I am wondering if we should not mess with that and leave how you have it. -- nvpublic