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([14.98.178.155]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-343e07156absm4838126a91.5.2025.11.12.22.49.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Nov 2025 22:49:46 -0800 (PST) From: Bhanu Seshu Kumar Valluri To: Vinod Koul , Jonathan Corbet Cc: dmaengine@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, khalid@kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, skhan@linuxfoundation.org, david.hunter.linux@gmail.com, bhanuseshukumar@gmail.com Subject: [PATCH] docs: dmaengine: add explanation for phys field in dma_async_tx_descriptor structure Date: Thu, 13 Nov 2025 12:19:37 +0530 Message-Id: <20251113064937.8735-1-bhanuseshukumar@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Describe the need to initialize the phys field in the dma_async_tx_descriptor structure during its initialization. Signed-off-by: Bhanu Seshu Kumar Valluri --- Documentation/driver-api/dmaengine/provider.rst | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst index 1594598b3..f4ed98f70 100644 --- a/Documentation/driver-api/dmaengine/provider.rst +++ b/Documentation/driver-api/dmaengine/provider.rst @@ -411,7 +411,7 @@ supported. - This structure can be initialized using the function ``dma_async_tx_descriptor_init``. - - You'll also need to set two fields in this structure: + - You'll also need to set following fields in this structure: - flags: TODO: Can it be modified by the driver itself, or @@ -421,6 +421,9 @@ supported. that is supposed to push the current transaction descriptor to a pending queue, waiting for issue_pending to be called. + - phys: Physical address of the descriptor which is used later by + the dma engine to read the descriptor and initiate transfer. + - In this structure the function pointer callback_result can be initialized in order for the submitter to be notified that a transaction has completed. In the earlier code the function pointer -- 2.34.1