From nobody Wed Dec 17 08:51:05 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2AED415C158 for ; Thu, 20 Mar 2025 23:04:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742511878; cv=none; b=nJB7br9oJlzuD3qbwMWjFbo4r3JjQPhDAbn0gVp/BRAfFbdxRSHtPEp5l8Of5PD5u5hMfg/iPd3QMYvcyf/VKhGQ/d/mhMXG6kNHCak6bGgZqhwWISTlr/ZoR7QWQVw2H9GT4vJQnzQinZtatT6CK7cRUnmH7kH7vzzQnWRJjhQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742511878; c=relaxed/simple; bh=Lha/2v4/99WRRqn+EErsa69RBL6tgvybSJRRwdSrAIY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=j5kl4neVP28my8ZM1TUgUHRGKxS/I34mmNdVAH2H0kXmK9a80QFDqIIKbNTRGAhrJCP3w72ZbJ8O5ePnKI2OprjJd03VoogLESiROzNWP9VYOdGjD5gS9FX++U4Wee/4V7R4n3eoYHc4zWOiZ4Snlxtjz64/2HU23wEGNu+x/Zg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VwwM0iKE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VwwM0iKE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E5C5C4CEDD; Thu, 20 Mar 2025 23:04:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742511877; bh=Lha/2v4/99WRRqn+EErsa69RBL6tgvybSJRRwdSrAIY=; h=From:Date:Subject:To:Cc:From; b=VwwM0iKEhRYz3EN6IyWVqKG7KHgeX6tyc86fD9IsQFPR3ao+Vr0qfOd7sCSKUneKM Ncfic+3Zius4uxlzUrLbY3PoDOfCTsL7Zcuil/TXKuW5Pw6JmCAZGFZhs89tJ8mfg8 hNwZzTMbMMiIHjIuucPHXmstmfhuCFZ9W8i7n6Ug2WacBecwH+0VVApyFSod0VYx3B v1KOMakchXvLle9PYoRWBZ5/hWuaofKycu3UGSH8T1l1PLNjjT26zeWhSFvAOClbCF Ylusb6XfW3WqnsKEaF2nL4a0ffNjniTxxz9U3+mUwaUw28B5zl7SLKH/hvI5wkHU+A t1uj4+6JOdPkA== From: Mark Brown Date: Thu, 20 Mar 2025 23:00:34 +0000 Subject: [PATCH] regmap: spi: Don't use spi_write_then_read() 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="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250320-regmap-spi-write-read-v1-1-31666bc6ebe8@kernel.org> X-B4-Tracking: v=1; b=H4sIABGe3GcC/x2MQQqAMAzAviI9W5gVUfyKeJhb1R7U0YkKsr87P CaQvBBZhSP0xQvKl0Q59gxVWYBb7b4wis8MZKgxNRlUXjYbMAbBW+XkLKzHbiJHlp031EJug/I sz/8dxpQ+0pMnXmcAAAA= X-Change-ID: 20250320-regmap-spi-write-read-8b2c2aecd027 To: Arnd Bergmann , Petr Tesarik , linux-kernel@vger.kernel.org Cc: Mark Brown X-Mailer: b4 0.15-dev-1b0d6 X-Developer-Signature: v=1; a=openpgp-sha256; l=1654; i=broonie@kernel.org; h=from:subject:message-id; bh=Lha/2v4/99WRRqn+EErsa69RBL6tgvybSJRRwdSrAIY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBn3J8DOH6OMDtzsqfq7QJ1U0hLffs0ZQUyHGB7Vgku M6CQvCKJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZ9yfAwAKCRAk1otyXVSH0PvZB/ 93NhCtzAMBgnQw+dWvqn1lvq0vlkOnr6KBzornmQozHE53O339E2UdhSvEbJFtygMKcezOkSZc6HpL sI3vwlpQ1tBHyKyAUXxHuMdWdt87J0tO2ooDoeeccqU7TpJG//E1KHjlQYpbL03Sv/XkxFnCWY83CW vuXUMV8p7RUjf73+PwHQ7VcvvH0lmz22CY2LkUzL/kJgl0ZciBaJtgNOIqe3yQPx8EGANZ3Vb4aqoJ tZBXD5PksN2nfW5mk4WN5qAU+muL4cpwTuj6vjMjtXrXbsQls5yEPSLVABOR7wRyc5ItXdrLI4cd/h dh+0Cw5N71gSOO3yTdYx/V7Bq7JCIq X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Currently SPI reads are implemented using spi_write_then_read(). This is a convenience API which as well as constructing a SPI message from parameters basically the same as for a bytestream read operation also bounces things into a memory buffer to allow callers to use stack or other non-DMAable memory. Since regmap should already be ensuring that everything can be DMAed further up the stack this copy is redundant so switch to using the underlying spi_sync() API with the buffers provided by the core directly. Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-spi.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-spi.c b/drivers/base/regmap/regmap-= spi.c index 14b1d88997cbe406c8900f5032d768fc7484e99f..6a3dbc217e890d25a392fd3157f= 9ed89188afdaa 100644 --- a/drivers/base/regmap/regmap-spi.c +++ b/drivers/base/regmap/regmap-spi.c @@ -94,8 +94,15 @@ static int regmap_spi_read(void *context, { struct device *dev =3D context; struct spi_device *spi =3D to_spi_device(dev); + struct spi_message m; + struct spi_transfer t[2] =3D { { .tx_buf =3D reg, .len =3D reg_size, }, + { .rx_buf =3D val, .len =3D val_size, }, }; + + spi_message_init(&m); + spi_message_add_tail(&t[0], &m); + spi_message_add_tail(&t[1], &m); =20 - return spi_write_then_read(spi, reg, reg_size, val, val_size); + return spi_sync(spi, &m); } =20 static const struct regmap_bus regmap_spi =3D { --- base-commit: 4701f33a10702d5fc577c32434eb62adde0a1ae1 change-id: 20250320-regmap-spi-write-read-8b2c2aecd027 Best regards, --=20 Mark Brown