From nobody Tue Feb 10 16:18:37 2026 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 B21B7311C2D for ; Tue, 3 Feb 2026 09:34:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770111281; cv=none; b=tlnXdrHcRA1UlxcO0/yvFr9zWmAg6rVF4EEhAVZSf78vj95KYEuRt22gZ483fEraw3t51ZobGLHN3l8369V4CUeaAHLO8pHuKnCQCBtMC31zm74eKv8RqbO/VunBHspLdTeztfyGlphzLzpldKybGoZNubtgZZpc5Nb5Gt8wU7s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770111281; c=relaxed/simple; bh=PIdksg1G07VqhZfWxWeVIPUH6eFQdZq3KZLVRtFrqR8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FkBtENAsJT8N+OyH2qKyHRjGxT2rWhR6zxMnnyRJClY1hNZVpzz1vy586RLKwBOV/cNl1iuD40Enklb0DiPiA1WZH9kEFxvh1rIukJvTKeWoGqR++zK2CWF+jKdxeT8XQZ6buSAslZs7gcS5alTTl4PAaL6SvJha4ofioG70gKA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vnCnr-0003ld-QA; Tue, 03 Feb 2026 10:34:35 +0100 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac] helo=dude04) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vnCnr-003slY-31; Tue, 03 Feb 2026 10:34:35 +0100 Received: from ore by dude04 with local (Exim 4.98.2) (envelope-from ) id 1vnCnr-0000000Ah9n-0nsS; Tue, 03 Feb 2026 10:34:35 +0100 From: Oleksij Rempel To: Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , David Jander Subject: [PATCH v4 07/13] iio: dac: ds4424: use fsleep() instead of usleep_range() Date: Tue, 3 Feb 2026 10:34:27 +0100 Message-ID: <20260203093434.2548978-8-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260203093434.2548978-1-o.rempel@pengutronix.de> References: <20260203093434.2548978-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The DS4422/DS4424 and DS4402/DS4404 datasheets do not specify a minimum delay between power-up (POR) and the availability of the I2C interface. The driver previously used `usleep_range(1000, 1200)` to enforce a ~1ms delay. Replace this with `fsleep(1000)` to allow the kernel to select the most efficient sleep mechanism (usleep or msleep) while retaining the existing conservative delay to ensure device readiness. Signed-off-by: Oleksij Rempel Reviewed-by: Andy Shevchenko --- changes v4: - New patch --- drivers/iio/dac/ds4424.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c index 5709d8a39d7b..94803885d735 100644 --- a/drivers/iio/dac/ds4424.c +++ b/drivers/iio/dac/ds4424.c @@ -241,7 +241,13 @@ static int ds4424_probe(struct i2c_client *client) return ret; } =20 - usleep_range(1000, 1200); + /* + * The datasheet does not specify a power-up to I2C ready time. + * Maintain the existing conservative 1ms delay to ensure the + * device is ready for communication. + */ + fsleep(1000); + ret =3D ds4424_verify_chip(indio_dev); if (ret < 0) goto fail; --=20 2.47.3