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[86.30.250.44]) by smtp.googlemail.com with ESMTPSA id x83sm2964625wmb.42.2019.06.18.08.12.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Jun 2019 08:12:01 -0700 (PDT) Subject: Re: [PATCH] dmaengine: qcom-bam: fix circular buffer handling To: Sricharan R , vkoul@kernel.org Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <20190614142012.31384-1-srinivas.kandagatla@linaro.org> <2d370a33-fa16-45ca-cf82-9d775349f806@codeaurora.org> From: Srinivas Kandagatla Message-ID: <544851f6-58b8-2506-01ce-5c4d1f93fb3c@linaro.org> Date: Tue, 18 Jun 2019 16:12:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <2d370a33-fa16-45ca-cf82-9d775349f806@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/06/2019 15:56, Sricharan R wrote: > So MAX_DESCRIPTORS is used in driver for masking head/tail pointers. > That's why we have to pass MAX_DESCRIPTORS + 1 so that it works > when the Macros does a size - 1 Isn't that incorrect to do that, pretending to have more descriptors than we actually have? --srini