From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (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 4D5DC1E871; Tue, 27 Feb 2024 16:59:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.22 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709053199; cv=none; b=mJ6RVRwyz0gzThzo1+O7bvFIJGaa/uP3gosKgdco29zhNupWDdKGTvy6TZnXGAKZPHkmcYnQFkHOstsKt0RdKbwRxjJnuFe0brwWgFNYx1M1mmmKbggk/EsHnpPA00XXAiT/v1oIYDDFCnW2+Kw8havgURreRrqatowjDKfHY2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709053199; c=relaxed/simple; bh=/B7LelH4C9+7KN5snCerIQZt9DJfVqzKB8tK+DeSzIU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Q502uOHho2CWnRNCxi/+SE/WdQUfjczvTfgZu2Uj4t8NaauttT/y+1JQ29wr8n0av73PgH7f46D535cZ1QZi08CCujPZHMI1aC/65s9sKhWGgEKsPgFyggy5p1UuZ2ohyeKT3QN3eSb58YU+BY4566TPU4LjhUvB2Ip0TpUlLes= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.net; spf=pass smtp.mailfrom=gmx.net; dkim=pass (2048-bit key) header.d=gmx.net header.i=wahrenst@gmx.net header.b=lTuy1O/O; arc=none smtp.client-ip=212.227.17.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.net header.i=wahrenst@gmx.net header.b="lTuy1O/O" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1709053183; x=1709657983; i=wahrenst@gmx.net; bh=/B7LelH4C9+7KN5snCerIQZt9DJfVqzKB8tK+DeSzIU=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From: In-Reply-To; b=lTuy1O/O9F96ZLgrvw3CbNNnT7wlFbteL9hKwcLY9KFiocmxXqnMrTtSdD6+K/Rl xb0WZHsqWb2r3HdJzfNFMK5CAqcKR5XMf1n+6/pl+uaaa7qNaB5Lyet/74Mzk4PxD G3ve9tShKZ9EyrpgEgnofulTLUyNqG1/lht2qJ8Akoz4CdQH2Y76A/AZ/H5kwcFiR dwe5bdXivLC9iB2z3FNClQw6gokZMbKIEO47h7uaMt3UDjPmIT0womX0e+pceQ7a5 rvUEAk912pbDX5yy2b1V51LrIEqBwVsFxXo8zSYlQOLTLfH2NlxkcxzniliJP3nAh 6/40CYGYrMMAt68M5A== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [192.168.1.167] ([37.4.248.43]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1N0X8u-1qitpr2cQ0-00wRse; Tue, 27 Feb 2024 17:59:43 +0100 Message-ID: <3e65fd65-ccfc-4a77-8934-52791662bdce@gmx.net> Date: Tue, 27 Feb 2024 17:59:40 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V4 2/2] pwm: Add GPIO PWM driver Content-Language: en-US To: Chris Morgan Cc: =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , Rob Herring , Krzysztof Kozlowski , Conor Dooley , andy.shevchenko@gmail.com, Angelo Compagnucci , Philip Howard , Sean Young , Linus Walleij , linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, Vincent Whitchurch References: <20240204220851.4783-1-wahrenst@gmx.net> <20240204220851.4783-3-wahrenst@gmx.net> <65de00aa.540a0220.f1081.6933@mx.google.com> From: Stefan Wahren In-Reply-To: <65de00aa.540a0220.f1081.6933@mx.google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:4iuxu59Rwv26h5ynZ7P87p2WwtTz/IbU6nbihWne8+8BnV6ieQu XRj9F9Nd5PLHtS87JAk2JnHKRMbmn1Gf4BEKgAhLHK0/ycdwY7wqP/ejND3fTIuj+xLbUOe 1uSvzMndZzdtwpKZ1G0kmgxo3tPGX1ekb/KtsLoc4VuR4USymZsYxqmGZ9Rp/mOCQ0zl6S4 1iX8WmTDzTZi5vuwDCU7A== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:EbUIyjHgN24=;zGsFF/y1JP3Oy+HkmHN9SSxfqP9 W+AENJfWf+TxN9Ht4xUfeXpZ1bd2F1rstI15qaIWy4kndULOAHb4A2eU8JbVDLX2zcockTHHF kjC4ZecSlQIUJtHP2WY7ZPEWpewBqNM7t5iOv5Dxjt6uI+r5UUXtcYqylyov9X7WzbuDnqCl0 LnopYxXaqLrcqEwFfZRl5O4pDp+4KQ0ggOKefeVVTFhRi7S3IKY/WI4m3ev3YYp90PGhSMcsQ 8i0PriNS/bwN6N70fodrejlmLaLPnvUez3b9YOllLfrfcIAk07V59CoLjpBAnUXFlQUNuPT3h ATd5EhFYdbSQarcSqgNv6Z8RWFGvULniZgpkB0FItDgAudJ7RyPCmTF1DTs4297omg0RUTrdC eARZcc10d4HJxc7c5DRZdJ3NTon7XpuNp6ceXGuQiK35IFwD45z3WL4JZIbpgOWWMZLiDPEu9 0HysrC/VvCAmwOfuFzxiNFNlQ7QCg4n2G/bqWVFnBY+XAzYYtmpq9ADeU1TXyf8CqASPnD8CF GkI3+wDNXC9p1ylX7oxnBy77VZXpB1EmL8BixHEAX8/1V+N25xinmzk6NRT3FRyNRaCCn5Ybi RolUFJ3USov/a9n+j2NSfUSM7fvAEHH92FnVdh+A7nLnd7g8XlsWgLeNjn4AYRb4vOiXItUno Qu5GAj+ZxJpA1Ba75Y29BsAKMqIH96BWUNx+woBxgEHZqUxkCI4SWkUCKwZdGLCu0WG2Yxntq KEQIzlnjBRtBmZGGondbbHrr9vHtWN6QxBXBmUWAKALca+MdJ9eyyoYAkIMdkGOa83macJBJy RfefVNyhzZ6tdCgKep4M27S9IAWBRJoZAoTYpeYpFsyAI= Hi Chris, Am 27.02.24 um 16:32 schrieb Chris Morgan: > I have a series of devices with GPIO controlled force feedback that > this driver helps us control better. So I'm looking forward to this, > thank you. Thanks for testing. I didn't had much time recently and i was fighting with hr timer resolution stuff. But will try to send the next version in March. > Note that when I set the resolution too low (I got confused and set > the period to 255) my device locked up hard and only a forced > power cycle could bring it back. Unfortunately this is a general design issue by driving the GPIO by a kernel driver and "expected" behavior. I didn't have a good solution for it yet. What period is too low without limiting other users? The only idea which comes to my mind is to introduce a kernel parameter for this driver to set a lower period limit. This can be provided by some administrator or system designer with enough experience. So a general user doesn't need to care about it. Best regards > Tested-by: Chris Morgan