From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5A446425864; Thu, 16 Jul 2026 14:01:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784210488; cv=none; b=KYnPiFm0CDkPC+c887r+BZBQkeQiw77BhqM/yKMT9rjU2Wg6AOis0Mp+kAQ38t/aTLf3NnLXe3PVrQvWVHMj6ZU/oeAUHlz/GhnMKUXbwH5OUiOHtzw8IG9OxicShxmGYjTaANlGIueRFvv4NpjhueOGjqOo+EUDFv9PJZiEFEQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784210488; c=relaxed/simple; bh=H1pVIiz2UoCBXSEnYaKxblfCKxklRMW+xkyDXt2p6xQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Itn5z3fdQr9ZCe0vZNWcTda1dEF0ugL69yiDjxJHed3GuTSMl3MxEWA88e8AG5jjOXZ2XBftHDu3XT1iHE6SCMtDclAgqv1J2ydJ+1GNBupOhCQfBSPi78zS8JhSfo+kfsbXUTxCsoPQq93WhdRNjIUnkp8Ah3vqWsLDqr36hBI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=e34ugAFc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="e34ugAFc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF22B1F000E9; Thu, 16 Jul 2026 14:01:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784210487; bh=yiWzQ4Z6VhlZ7VASysEsYEjVH5pIqoBNOzZnNFjv1iA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e34ugAFcFR3aDU5D2pz4o85MXZ9CeuwaxF7+SBSzu0wFCMVmnrJQKbaDvzc2eTG/T XfB4toUkj4r9lSsnPGODY8Dou0AcrAU9Zepi4psil9aBzzM3zv3kxhBo+POlgqPtMF MynuQ1G19qsc1Z4s2jr4EOTi6GFaesQxxih70fik= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stepan Ionichev , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 6.18 066/480] iio: gyro: bmg160: wait full startup time after mode change at probe Date: Thu, 16 Jul 2026 15:26:53 +0200 Message-ID: <20260716133046.137717626@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133044.672218725@linuxfoundation.org> References: <20260716133044.672218725@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stepan Ionichev commit 088fcb9b567f8723074ad9eb1bf5cb46f8a0096b upstream. bmg160_chip_init() calls bmg160_set_mode(BMG160_MODE_NORMAL) and then waits only 500-1000 us. Per the BMG160 datasheet (BST-BMG160-DS000-07 Rev. 1.0, May 2013), the start-up and wake-up times (tsu, twusm) are 30 ms. The same file already waits BMG160_MAX_STARTUP_TIME_MS (80 ms) in bmg160_runtime_resume() after the same set_mode(NORMAL) operation. The 500 us value at probe was likely a unit mix-up; the old comment said "500 ms" while the code used microseconds. Reuse the same constant via msleep() and add a code comment explaining the datasheet basis for the wait. Without this, register writes that follow the mode change can hit the chip before it is ready. Fixes: 22b46c45fb9b ("iio:gyro:bmg160 Gyro Sensor driver") Signed-off-by: Stepan Ionichev Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/gyro/bmg160_core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/iio/gyro/bmg160_core.c +++ b/drivers/iio/gyro/bmg160_core.c @@ -264,8 +264,14 @@ static int bmg160_chip_init(struct bmg16 if (ret < 0) return ret; - /* Wait upto 500 ms to be ready after changing mode */ - usleep_range(500, 1000); + /* + * Wait for the chip to be ready after switching to normal mode. + * The BMG160 datasheet (BST-BMG160-DS000-07 Rev. 1.0, May 2013) + * specifies a start-up / wake-up time (tsu, twusm) of 30 ms; use + * BMG160_MAX_STARTUP_TIME_MS (80 ms) as a safety margin, matching + * what bmg160_runtime_resume() already does. + */ + msleep(BMG160_MAX_STARTUP_TIME_MS); /* Set Bandwidth */ ret = bmg160_set_bw(data, BMG160_DEF_BW);