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 A662B20320 for ; Fri, 26 Jan 2024 23:49:05 +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=1706312945; cv=none; b=AgiBdGx9bd/wFwAmQDo2F8rQiX8n/Aq9aQUvd5rDwfZWLhe8ojamHdLpgZ8KdkG8I3bY8CW70s6uPA+A7sGCD+JmMZMYI40ELuu7NhExZS7w7dEWMDSvCN9U7b0fbEeYgvXr9rqjv98JjUw3hogl5MBkPnXlq6LfNfeVwwdBmdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706312945; c=relaxed/simple; bh=c7nyngLN1fgNnxaC6srPWWXh0rIk5CeTBbDjEAz/zHQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=go6nO2UtfTF1d9aaY6yu4rn48fsgHXHBopfjJYTImH9MCEW7TxMageUQi7bxOJ+EzmFJZiwp2yGCevchOAZy7utijX7xUHKvLuy6rsAdzTlVPfZSuPzqEpsvmcfg283lt4geCAVR65ZZdf50LNOStIjGigFTLT2jdIvGQ/THNE8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ehoWQ5rQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ehoWQ5rQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B8AFC433F1; Fri, 26 Jan 2024 23:49:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1706312945; bh=c7nyngLN1fgNnxaC6srPWWXh0rIk5CeTBbDjEAz/zHQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ehoWQ5rQ3zGh7ghfJ6ykHjVrThwzQiTBtap2TP8x7KmmYtzZdt+g3IjFMUcfiyuMH 7AstrjToY+PWwMUSUPnHzARiGLoe6WoNIFTsVrTiE1x2RH6VZgH4lqgvJQQqZNg674 hxC31V3AmCGmB5crvlSQiQJK2KeMHLst3Wb+w8B0= Date: Fri, 26 Jan 2024 15:49:04 -0800 From: Greg KH To: Hugo Villeneuve Cc: stable@vger.kernel.org Subject: Re: serial: sc16is7xx: improve regmap debugfs by using one regmap per port Message-ID: <2024012643-resume-pounce-39e6@gregkh> References: <20240123122957.9a88fb7839ae745975af6883@hugovil.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240123122957.9a88fb7839ae745975af6883@hugovil.com> On Tue, Jan 23, 2024 at 12:29:57PM -0500, Hugo Villeneuve wrote: > Hi, > I would like the following patch to be applied to the stable > kernel 6.6: > > 3837a0379533 serial: sc16is7xx: improve regmap debugfs by using one > regmap per port > > As noted in > https://lore.kernel.org/all/20231211171353.2901416-1-hugo@hugovil.com/raw : > --------------------- > I did not originally add a "Cc: stable" tag for the above mentioned > commit, as it was intended only to improve debugging using debugfs. But > since then, I have been able to confirm that it also fixes a long > standing bug in our system where the Tx interrupt are no longer enabled > at some point when transmitting large RS-485 paquets that completely > fill the FIFO and thus require multiple and subsequent writes to the > FIFO once space in it becomes available. I have been investigating why, > but so far I haven't found the exact cause, altough I suspect it has > something to do with regmap caching... > --------------------- > > It applies cleanly and was tested on this kernel using a > custom board with a Variscite IMX8MN NANO SOM, a NewHaven LCD, and two > SC16IS752 on a SPI bus. The four UARTs are using RS-485 mode. Now queued up, thanks. greg k-h