From mboxrd@z Thu Jan 1 00:00:00 1970 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 4312B28D83F; Mon, 12 Jan 2026 11:59:41 +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=1768219182; cv=none; b=sEmVOadlCYCr4xBP1RMDzcFOrZHeWW0RIer8FDeqaE5/p5VP2vHZi0IM1BJV8KafiuvLrifHmr8X+ZxemZWxzjv+zfJrKUXpgDsYveTudmgoRjy2rLcjFTfHW872kn+dJ83xxeSDQM+Bb0cl1KusaMzr29hY2Vjanq1iJ5zG3vw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768219182; c=relaxed/simple; bh=nv0QKn/vbK6AKnykyJsZSXuxhYtZBmMs+iKw2fPMln0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AhAresyAgm8Qaf4XctQUyNTJw/SXbEtMTCWWzVmnLgtDR76OgysDyOo5c9sj0obm4/KWfjwJ7WAfshgq3+/XRXHyeNlzf2Uurrew5uYP8bSR+TWLA/BkCWnXzqjJA7f2OgUZLh8/Eoucz+He+/QGpT4Yp/UNHmpl10QTXciwWU8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sqSAg0QB; 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="sqSAg0QB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF47AC19421; Mon, 12 Jan 2026 11:59:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768219181; bh=nv0QKn/vbK6AKnykyJsZSXuxhYtZBmMs+iKw2fPMln0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=sqSAg0QB1lXgQ4bA0QpCPnvJdMK/EH2VJPGX3YAK3iCVLrhnyj3HYOWGV/y8HKF+i t9cqlLNl7FN8CUy6SluDwYnlkcIXg13GODglsEtcMu+g3WY6mOoLIJBZjc9rUBwJwZ CfS9Nd8BZ3ePnnUAh2g4HAthif44RMukC6Pie5z7p3An88BQFC1SNmUFZ2pBRt+lS9 6WqLqXBDLF2toBFgc1Ej4vZVH6FFAVFiUd+QT5NBxe2pLA/sliNR5rzvWNFkhhGaz+ Zupc9p0TtLiv+4iCsrhgPUWa56t11av+FwEbYZRWoIviyt9Oxyjo6IkTF6T0sibnxQ n1rkCdbEKPwMg== Message-ID: <6126ae90-6f46-46f4-9a28-1b8d7ef69277@kernel.org> Date: Mon, 12 Jan 2026 11:59:38 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] media: i2c: imx412: wait for NVM read (T7) before programming mode registers To: Wenmeng Liu , Sakari Ailus Cc: mchehab@kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260109044913.3310-1-wenmeng.liu@oss.qualcomm.com> <1344ad43-a4c4-4e37-ae4e-eddd2c577b3f@oss.qualcomm.com> <468ce093-7704-4497-a538-c54baacbd8ae@oss.qualcomm.com> <828597fc-ec02-488c-99e9-418a7ff266d3@oss.qualcomm.com> From: Bryan O'Donoghue Content-Language: en-US In-Reply-To: <828597fc-ec02-488c-99e9-418a7ff266d3@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/01/2026 11:50, Wenmeng Liu wrote: > -- if disable gpiod_set_value_cansleep(imx412->reset_gpio, 1); form > imx412_power_off, the issue will not happen. Yeah this is basically what I said in the last email. The state transition diagram for starting the part will assume reset is asserted. So in power_on() - you need to assert reset prior to powering on and clocking the part - which is the eqivalent logic to what you posted above. The reason you should do this in power_on() is it doesn't assume power_off has run first. power_on should establish the initial conditions required to power on the device, in this case, we've established you need to have reset asserted first. --- bod