From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.mainlining.org (mail.mainlining.org [5.75.144.95]) (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 E258C7083C; Sat, 29 Aug 2026 10:28:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=5.75.144.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787999318; cv=none; b=L1c/+4GyPOxCaFSRwh1r32t875SOewA9Y8XGJBctfEiAj0R32C0mF1CP+aNHBUgE/sZ9AJe2Riw4uWwWb6GgcHcKlfS1SFyyN/9LNnbyohI5DwRaQiZqWzqC9cu5D5tmHqvWCpX8kZmphNApAKtYRnn25hmPe+NHQCiqgeXzuFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787999318; c=relaxed/simple; bh=GsBhpbOLrySC99dIaT34f6OHVks3jkxuW/tLp7ccDL4=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=foLJD6DqZLqFkEvmOdf2DX/wSL1DiWG+REdG12xNFl00o7xGILV6w8nYx6tlXcNKK3PtS3pRpwvQzhrEhnZVTg7Chup5GgZX+M6KBUSkedsNH+m0NI4AFvf9t7RtSSoii5IWk3pja1gqtaOjzo3727YBauKTx2Lxk5LExKi+WUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mainlining.org; spf=pass smtp.mailfrom=mainlining.org; dkim=pass (2048-bit key) header.d=mainlining.org header.i=@mainlining.org header.b=HsEzYRps; dkim=permerror (0-bit key) header.d=mainlining.org header.i=@mainlining.org header.b=yZbbCKsf; arc=none smtp.client-ip=5.75.144.95 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mainlining.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mainlining.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mainlining.org header.i=@mainlining.org header.b="HsEzYRps"; dkim=permerror (0-bit key) header.d=mainlining.org header.i=@mainlining.org header.b="yZbbCKsf" DKIM-Signature: v=1; a=rsa-sha256; s=202507r; d=mainlining.org; c=relaxed/relaxed; h=To:Subject:From:Date:Message-ID; t=1787999313; bh=svRVpfKt7DAf1SNL4xmrqzo nRN0pWlMpZ8nBCldd458=; b=HsEzYRpsoUYyFSr0Wrdwaxb0zYooif00UcYtRkFS3z/dNvHjFC D0Gxs/TafSTOoOWWvwEKJyAxhrKqdLKSKhk6ong84CGSrA23JoE5YxASQXeeq7fIU6sAeiw7KL7 z4a9nPiEEJrnAqZfBv20HO7oE1dPE7u9UvLROB62W2vRmIpYeLoOQOBQf+RYzLsRRFQi/FSx14T YjlEgVVpfyggpTR7vQ+8wjUxuuW0Z2Y83x9SW/8dPar0z8/tmjI3yZZ7MOiGuG1P85Be17rbq+R epuV6tCKg3nsbkOegxeOzvHukYV/fRqe1q6C3j4zRGd6BD9LERLPuXS681fFD0h/rUw==; DKIM-Signature: v=1; a=ed25519-sha256; s=202507e; d=mainlining.org; c=relaxed/relaxed; h=To:Subject:From:Date:Message-ID; t=1787999313; bh=svRVpfKt7DAf1SNL4xmrqzo nRN0pWlMpZ8nBCldd458=; b=yZbbCKsf5GPpyRDBa5GQeCmYDWbbHizw7Io3KQLP9xEPiYEoV2 6J1IXwLB0HzkP1Ncm+Dmf+dq2sXpG/g7F7Dg==; Message-ID: <8ad49542-e88d-4ac0-ab12-ef84382d96d7@mainlining.org> Date: Sat, 29 Aug 2026 13:28:31 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Muzaffer Kadir Subject: Re: [PATCH] media: i2c: imx258: Add reset-gpio support To: =?UTF-8?Q?Ond=C5=99ej_Jirman?= Cc: Sakari Ailus , Mauro Carvalho Chehab , git@luigi311.com, pavel@ucw.cz, tomm.merciai@gmail.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, phone-devel@vger.kernel.org References: <20260828-imx258-add-reset-gpio-patch-v1-1-633972d2a700@mainlining.org> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Ondřej, On Fri, 28 Aug 2026 20:16:30 +0200, Ondřej Jirman wrote: >> @@ -1128,6 +1130,18 @@ static int imx258_power_on(struct device *dev) >> if (ret) { >> dev_err(dev, "failed to enable clock\n"); >> regulator_bulk_disable(IMX258_NUM_SUPPLIES, imx258->supplies); >> + return ret; >> + } >> + >> + if (imx258->reset_gpio) { >> + ret = gpiod_set_value_cansleep(imx258->reset_gpio, 0); >> + if (ret) { >> + dev_err(dev, "failed to deassert reset\n"); >> + clk_disable_unprepare(imx258->clk); >> + regulator_bulk_disable(IMX258_NUM_SUPPLIES, imx258->supplies); >> + return ret; >> + } >> + usleep_range(400, 500); >> } > > There are two times given in the datasheet. min 400 us between reset deassert > and ID register read over CCI. And minimum time between deassert and stream > start, which is 12ms. > > https://xff.cz/dl/tmp/b8efc244280a2b35.png > > https://xff.cz/dl/tmp/ed9b967a140bd347.png > > I wonder if this driver satisfied the second constraint. That may perhaps depend > on how userspace uses it. Thanks for datasheet timings. There is an existing software reset and 12ms wait call inside imx258_start_streaming function. It should satisfy stream start. Please correct me if I am wrong. -- Best Regards, Muzaffer Kadir