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 7E5014582C8; Tue, 21 Jul 2026 21:08:54 +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=1784668135; cv=none; b=nUid+m+wh89FBbj/hTCGXyPH5jeaXaJS6AJ8Oj2YGGuEq2FAh24tvRblFyuvcjf5BEszjh5y2AyedwC4xxCEzOSE4sEKNgbjhLOSJGAkpjUnwVR6+kGeK8lqu6jPrFdtAQW6nt+JgL8/dNjkAN1MHhabU8EEhLO6yZw0VEwtYrI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784668135; c=relaxed/simple; bh=hy1N44p2JZUKOp22AT79d/BkaZWjf+hl5lB5dgKdWfY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mfYBbmbiR17X0FZ801VEerPtExYlZf6VA5YfzwmNF42mcPGrhW0Cx1W7kxS/j92dn0O8uFTnatQOw1hbHHA3VP2pCETd6qMEHdtkp7dYKz01pj/qngw0hSxzZOJm5ra1dAsQfepreSNmLVjZolotKksVrAc8uX5W1VvkCQmj5l0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Du4jCnYN; 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="Du4jCnYN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E531C1F00A3A; Tue, 21 Jul 2026 21:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784668134; bh=BxtUKMxdcdpHGuiTrl2EXEID2RpXcMyPn0OjEjbItOA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Du4jCnYNsSkiujsvjysTiGL56NJS0zhCcgiMbmBKaRVCT2CkQ7RV5K6xxiHD316Ht 4OKuxa7AIzhXe6NMOBI/Ux7y9yJRDtCszFHCrOgKbmD7cb7afw8D9Li3OEz3frKMsX Iz3nRzKMBghIuM5cWzCYljqXxPqHUaNrdiBpdsTY= 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 6.1 0062/1067] iio: gyro: bmg160: wait full startup time after mode change at probe Date: Tue, 21 Jul 2026 17:11:03 +0200 Message-ID: <20260721152425.955443674@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@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 6.1-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 @@ -268,8 +268,14 @@ 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);