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[90.182.112.124]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c296608dc91sm589042266b.39.2026.09.15.06.17.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Sep 2026 06:17:17 -0700 (PDT) Date: Tue, 15 Sep 2026 15:17:16 +0200 From: Joshua Crofts To: Abdelnasser Hussein Cc: jic23@kernel.org, gregkh@linuxfoundation.org, nuno.sa@analog.com, Michael.Hennerich@analog.com, dlechner@baylibre.com, andy@kernel.org, linux@analog.com, linux-iio@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 0/3] staging: iio: adc: ad7816: Fix SPI operations race condition and DMA safety Message-ID: <20260915151716.000011c9@gmail.com> In-Reply-To: <20260915075939.18180-1-abdelnasserhussein11@gmail.com> References: <20260915075939.18180-1-abdelnasserhussein11@gmail.com> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.51; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 15 Sep 2026 10:59:36 +0300 Abdelnasser Hussein wrote: > This series addresses separate issues in the ad7816 driver regarding > race conditions and DMA safety across all SPI operations. > > Changes in v7: > > Patch 2: Moved the mutex to the top of the ad7816_chip_info struct > (right after the pointers) to prevent struct padding/holes, as > pointed out by Andy Shevchenko. Also expanded the mutex to serialize > ad7816_spi_write() to prevent race conditions. > > Patch 3: Dropped the dedicated rx_buf. Switched all spi_write() and > spi_read() calls to use spi_write_then_read(..., NULL, 0) to safely > handle DMA using an internal bounce buffer, avoiding cacheline sharing, > as guided by Jonathan Cameron. > > Changes in v6: > > Separated the alphabetical sorting of include headers into a dedicated > precursor patch (Patch 1). > > Kept the mutex addition strictly focused on serializing the read > operations without modifying the sizeof() argument (Patch 2). > > Moved the sizeof() argument fix to the DMA-safe buffer patch where > it logically belongs (Patch 3). > > Changes in v5: > > Split the changes into separate patches for bisectability. > > Replaced stack buffer with a dedicated rx_buf aligned with > IIO_DMA_MINALIGN. > > Abdelnasser Hussein (3): > staging: iio: adc: ad7816: Sort headers alphabetically > staging: iio: adc: ad7816: Serialize SPI operations > staging: iio: adc: ad7816: Fix DMA safety issues in SPI transfers > > drivers/staging/iio/adc/ad7816.c | 29 ++++++++++++++++++++--------- > 1 file changed, 20 insertions(+), 9 deletions(-) > For the whole series: Reviewed-by: Joshua Crofts -- Kind regards, Joshua Crofts