From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.manjaro.org (mail.manjaro.org [116.203.91.91]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ADA111FB89A; Wed, 13 Nov 2024 10:38:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=116.203.91.91 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731494329; cv=none; b=g3jwqACMea0gympLPBP/mvMcTpPCxVfGOghT0br00FszEutI85giBfMuY2r3SLCc0iyQj1P8f3yaGzdReUoLbPlOEBdWafxuA03OYKPxjmvN4UWOt/OcHbn62cr9Tcilbe/ju1ebL2xb27N5sTTKuAtR7kA254iBUPaQkoLNQuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731494329; c=relaxed/simple; bh=XnyK2cUNddDaNwEG52WGnzjL8TynPLpzNBm8cJx3Jmw=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=HDoZ8ejKW16buSmz+P0vZwpbxsy5zf7kDJvjmce12w2GGgkDs6MpDSP8YA78UNppGGBxktWsVBXsDEdHdCTKx3ev13NFSAC3VTrZNwU1xKiKiM7Pi/+R73kD2fcLQgDhDlrtXArm5fjG9DTrwycSBKbP1vnlwWr63bzQRGBEBPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org; spf=pass smtp.mailfrom=manjaro.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b=TP7jCWIz; arc=none smtp.client-ip=116.203.91.91 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=manjaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b="TP7jCWIz" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=2021; t=1731494319; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IF/vepkYLlzPa+ADSxysQyPEUO3lIiqkFDR8yTHUMM4=; b=TP7jCWIzDHOvG6IaVPJw1zfuuw2FKJ1Bh0h2H/+0gswy1ADCLGYi2WQoTvzZ9ssMgdIryY vIu232el3rCYgagbcyYlswLfXcQ2pWLLb7rBWrC6C8tlENyR7M8FHIYXDZvRiG/di/llH4 WMgmzq9Wwuq3+IorsKn6hlakinn3tNSpUOaxEAgo8Ow6HqCCo+i7KD/W4XpP2CdfDSQESe qJto4tSlZESB1jp7tTw7La4pvWBCmrwsuagTnmmlYJ7esUk8/7JMfhqJ0HfZvTZXs6r7Wu VKuw19CI5tcn5LNyZfxXC5ty+YjPXelReeTEARGVXGYe/ryfajlFwbt6MnqFNA== Date: Wed, 13 Nov 2024 11:38:37 +0100 From: Dragan Simic To: =?UTF-8?Q?Tam=C3=A1s_Sz=C5=B1cs?= Cc: Jonas Karlman , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , FUKAUMI Naoki , Chukun Pan , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] arm64: dts: rockchip: Enable UART8 on rock-3b In-Reply-To: References: <20241111181807.13211-1-tszucs@linux.com> <20241111181807.13211-4-tszucs@linux.com> <4ba81dfa-f276-4e05-b46b-92f50dbcfcc4@kwiboo.se> <9330ebb370780c001fd2aaee49aec9e8@manjaro.org> <0eb19e4daf2cdf3d4a04935876c3d3b0@manjaro.org> Message-ID: X-Sender: dsimic@manjaro.org Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Authentication-Results: ORIGINATING; auth=pass smtp.auth=dsimic@manjaro.org smtp.mailfrom=dsimic@manjaro.org Hello Tamas, On 2024-11-13 11:24, Tamás Szűcs wrote: > On Wed, Nov 13, 2024 at 12:25 AM Dragan Simic > wrote: >> On 2024-11-12 22:04, Tamás Szűcs wrote: >> > On Tue, Nov 12, 2024 at 4:07 PM Dragan Simic >> > wrote: >> >> Please correct me if I'm wrong, but isn't this UART supposed to be >> >> used for the Bluetooth part of an SDIO WiFi + Bluetooth module, in >> >> form of a non-standard M.2 module that Radxa sells? >> > >> > UART8 is supposed to be used for any radio module connected to the M2E >> > connector. >> > It will typically be responsible for Bluetooth or BLE but it could be >> > 802.15.4 or whatever. In any case, all wanting to use it will need the >> > uart8 node enabled. >> >> I see, but I'm still guessing what's the actual use of enabling the >> UART8 when it will remain pretty much useless without the additional >> DT configuration, such as in the WiFi+Bluetooth DT overlay that Jonas >> sent a bit earlier? > > The actual use is device enablement. Hmm, I'll need to think more about how it fits together. >> I think that the UART8 should be enabled together with something that >> actually makes use of it, which in this case unfortunately cannot be >> automatically detected and configured, so it belongs to a DT overlay. >> I'll get back to this in my next response. > > I agree, bluetooth blocks dedicated to specific modules should belong > to DT overlays. > >> >> With that in mind, I see very little sense in just enabling the UART, >> >> without defining the entire Bluetooth interface, which AFAIK produces >> > >> > Defining a bluetooth node would hardwire idiosyncrasies of a given >> > radio module's Bluetooth core. Sure you could add a sleep clock, all >> > kind of sideband signals for wakeups, reset, power down, etc. But hey, >> > some will use them, some won't. I think it's undesirable and >> > unnecessary. You can hciattach from here and most will work just like >> > that. Tighter integration or anything special, module specific on top >> > should be handled individially, on a case-by-case basis. This is a dev >> > board after all. I say trick of all trades. >> > >> >> nasty looking error messages in the kernel log when there's actually >> >> nothing connected to the UART. >> > >> > My dmesg is clean as a whistle >> > root@rock-3b:~# dmesg | grep -E 'fe6c0000|ttyS0' >> > [ 0.344818] fe6c0000.serial: ttyS0 at MMIO 0xfe6c0000 (irq = 26, >> > base_baud = 1500000) is a 16550A >> > What kind of nasty errors do you recall? >> >> Those would be the kernel error messages produced with the Bluetooth >> DT configuration in place, but with no SDIO module installed. > > These are the kernel messages related to UART8 with the uart8 DT node > enabled and an SDIO module installed. Out of curiosity, what M.2 module are you testing it with?