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([2600:8803:e7e4:1d00:58f0:670c:6b15:7fd3]) by smtp.gmail.com with ESMTPSA id 006d021491bc7-604a5c4bfafsm467955eaf.25.2025.04.16.11.43.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 16 Apr 2025 11:43:59 -0700 (PDT) Message-ID: Date: Wed, 16 Apr 2025 13:43:58 -0500 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] iio: adc: ad4000: Avoid potential double data word read To: Marcelo Schmitt , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: jic23@kernel.org, lars@metafoo.de, Michael.Hennerich@analog.com, nuno.sa@analog.com, andy@kernel.org, marcelo.schmitt1@gmail.com References: <8f765cfd6e93fad4e755dd95d709b7bea2a388e2.1744718916.git.marcelo.schmitt@analog.com> From: David Lechner Content-Language: en-US In-Reply-To: <8f765cfd6e93fad4e755dd95d709b7bea2a388e2.1744718916.git.marcelo.schmitt@analog.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/15/25 7:21 AM, Marcelo Schmitt wrote: > Currently, SPI-Engine offload module always sends 32-bit data elements to > DMA engine. Appropriately, when set for SPI offloading, the IIO driver uses > 32 storagebits for IIO ADC channel buffer elements. However, setting SPI > transfer length according to storagebits (32-bits in case of offload) can > lead to unnecessarily long transfers for ADCs that are 16-bit or less > precision. Adjust AD4000 single-shot read to run transfers of 2 bytes when > that is enough to get all ADC data bits. > > Fixes: d0dba3df842f ("iio: adc: ad4000: Add support for SPI offload") > Suggested-by: David Lechner > Signed-off-by: Marcelo Schmitt > --- Reviewed-by: David Lechner