From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from foss.arm.com (foss.arm.com [217.140.110.172])
	by smtp.subspace.kernel.org (Postfix) with ESMTP id 18AC11E5724
	for <linux-kernel@vger.kernel.org>; Fri, 20 Mar 2026 09:23:40 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172
ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
	t=1773998622; cv=none; b=dHCmU8lMf4uuVwQVX+u8boeTdxY0tJqwka1NtDPrOseg5TATUDpCcjRPVyQcaQMeMuMpbWGOipwG7UU02JC8bsgsE5bpWmHio+sRCDNLFWtcmgFlCZxhV76txa1aVIv2vE4frOlogoSoofxbquqwxdQGr2EFNycldoDT2bunKNI=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1773998622; c=relaxed/simple;
	bh=fqAV7Jc30eMhI0WkFzpCB+lPpiXQIAm35+jJ1DdJVeU=;
	h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:
	 Content-Type:Content-Disposition:In-Reply-To; b=px/u0dp0B8cRboPMw2r8OJtt/uw+7N9D4TuPUvHtHUBsY3mX+4o+NAdudP27JZ6cizehfsWVH58Jaup0yTMYemVt8WzLXbBMfJnuZ0Zw5zrodXWX5fwdjDzPqTphZbTd1jvCB/VJdgh05yGK7TZtU2GXjslB/CwgbjZBBhGAAag=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172
Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com
Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com
Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14])
	by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 364D91682;
	Fri, 20 Mar 2026 02:23:34 -0700 (PDT)
Received: from localhost (e132581.arm.com [10.1.196.87])
	by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D44413F778;
	Fri, 20 Mar 2026 02:23:39 -0700 (PDT)
Date: Fri, 20 Mar 2026 09:23:37 +0000
From: Leo Yan <leo.yan@arm.com>
To: Jie Gan <jie.gan@oss.qualcomm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@arm.com>,
	James Clark <james.clark@linaro.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Tingwei Zhang <tingwei.zhang@oss.qualcomm.com>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] coresight: platform: check the availability of the
 endpoint before parse
Message-ID: <20260320092337.GP8048@e132581.arm.com>
References: <20260320-add-availability-check-v1-1-b2e39cdeb6e0@oss.qualcomm.com>
 <20260320082549.GO8048@e132581.arm.com>
 <519ca61b-049e-4e2f-a9fc-9b4621574470@oss.qualcomm.com>
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <519ca61b-049e-4e2f-a9fc-9b4621574470@oss.qualcomm.com>

Hi Jie,

On Fri, Mar 20, 2026 at 04:44:54PM +0800, Jie Gan wrote:

[...]

> It's about the coresight_find_device_by_fwnode() returns NULL, resulting in
> -EPROBE_DEFER. So the probe process will re-start after several seconds, but
> always failed because we have a "disabled" device node in DT(we can see this
> device in DT, but it never becomes available). It's ok if the device only
> has one remote device, but has issue with more than one remote devices.
> 
> Consider below situation:
> 
>       device0
>    |          |
>   device1  device2(status = "disabled")
> 
> The probe of device0 succeeds only when device1 and device2 are available at
> probe time. But I think it's ok to probe the device0 only with device1
> available.

Thanks a lot for details.  We might need to report warning or error if
all remote endpoints fail (e.g., device1/device2 both are disabled),
this is a rare case so would be low priority.

For this patch:

Reviewed-by: Leo Yan <leo.yan@arm.com>