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[2a02:3100:b260:f201:9983:e8c4:aff5:7a36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49e6576122bsm145786115e9.2.2026.09.11.23.55.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Sep 2026 23:55:11 -0700 (PDT) Date: Sat, 12 Sep 2026 08:55:08 +0200 From: Karl Mehltretter To: Russell King Cc: Hans Ulli Kroll , Robin Murphy , Marek Szyprowski , Will Deacon , Arnd Bergmann , Christoph Hellwig , Linus Walleij , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 2/2] ARM: dma-mapping: flush FROM_DEVICE buffers on legacy backends Message-ID: References: <20260910063620.17768-1-kmehltretter@gmail.com> <20260910063620.17768-3-kmehltretter@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260910063620.17768-3-kmehltretter@gmail.com> On Thu, Sep 10, 2026 at 08:36:20AM +0100, Karl Mehltretter wrote: > The legacy write-back cache backends invalidate DMA_FROM_DEVICE buffers > when ownership passes to the device. A plain invalidate can discard dirty > CPU cache lines. If the device writes only part of the buffer, untouched > bytes can expose memory contents older than those present at the handoff. Sashiko flagged unused *_dma_inv_range helpers in its dashboard review of this patch [1]. I can remove the unused invalidate helpers in a separate cleanup patch in v2. [1] https://sashiko.dev/#/patchset/20260910063620.17768-1-kmehltretter@gmail.com Thanks, Karl