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 A1CA2248867; Thu, 14 May 2026 13:49:57 +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=1778766597; cv=none; b=ThlLZ/pMNaRJ4n/TzGvp3FkWjDe6K9/kkaajKZ6c9F0uGLggEifAiWAg1KGy/58NQ/XpYncEupk7m8I2tv8jPcZzzC0H1GfpObevGKwxWUDHYSPLeYvBdJvj0g27O7nd26kMn/aGfjUcKHoI1XcD32fkQtjtDPRn/4Bj8CduwZY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778766597; c=relaxed/simple; bh=ELBN6SwvwFihNqbqf8GHCVnp9QNV3fohvFqFQFtcqas=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MY+uqql941Vtj765/T54yqtaD6HgJopJBHBEViWYEBrp6TJfqF6deg+EpTQfvnkkHBrGzolpfIvgpmWNyLc9n0WQl3EOBTe0JPxZrR2bJSuHU2EUn3OSXas8fJFVkbVL6EH3nQDQ9CeqK+pXkXn0Zq+IR1n/vZMKkqBztWGkMlk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tc8rFlQ3; 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="tc8rFlQ3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFDD6C2BCB3; Thu, 14 May 2026 13:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778766597; bh=ELBN6SwvwFihNqbqf8GHCVnp9QNV3fohvFqFQFtcqas=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tc8rFlQ3Tip8Xyjkcs0setH/0pZui5J7W8jFdp3bMl0zBjdfgM4Xc/pvPljlejZN2 K9K8EMlweJXZ/hfgyk76uMtCkjCEgnqCsxDYRp8lsvQcMBKJYDo44TGRfErbcvime+ V+N6ehzD7glK0YUHsT48LiH3hiNNopymduEkIONw= Date: Thu, 14 May 2026 15:50:01 +0200 From: Greg KH To: Jianlin Lv Cc: corbet@lwn.net, skhan@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, jianlv@ebay.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, driver-core@lists.linux.dev Subject: Re: [PATCH] driver core: Add cmdline option to force probe type Message-ID: <2026051406-corridor-equation-c50e@gregkh> References: <20260514094955.76305-1-jianlv@ebay.com> <2026051443-exuberant-important-534f@gregkh> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, May 14, 2026 at 09:35:08PM +0800, Jianlin Lv wrote: > On Thu, May 14, 2026 at 6:16 PM Greg KH wrote: > > > > On Thu, May 14, 2026 at 05:49:55PM +0800, Jianlin Lv wrote: > > > From: Jianlin Lv > > > > > > Device drivers that use asynchronous probing can cause non-deterministic > > > device ordering and naming across reboots. A typical example is storage > > > drivers (like sd/nvme): asynchronous probing can lead to inconsistent disk > > > logical names after reboot. In scenarios where disk naming consistency is > > > critical, the probe type should be set to synchronous. > > > > > > This patch introduces a driver_probe kernel parameter that overrides any > > > driver's hard-coded probe type settings and allows runtime control without > > > requiring kernel recompilation: > > > > > > driver_probe=PROBE_TYPE_SYNC,nvme,sd # Force specific drivers sync > > > driver_probe=PROBE_TYPE_ASYNC,*,usb # Force all async except usb > > > driver_probe=PROBE_TYPE_SYNC,* # Force all drivers synchronous > > > > > > The implementation replaces the limited driver_async_probe parameter with > > > a more flexible interface that can force either synchronous or asynchronous > > > probing as needed. > > > > > > Signed-off-by: Jianlin Lv > > > --- > > > .../admin-guide/kernel-parameters.txt | 27 +++++-- > > > drivers/base/dd.c | 71 ++++++++++++++----- > > > 2 files changed, 74 insertions(+), 24 deletions(-) > > > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > > index 4d0f545fb3ec..b43a8bd20356 100644 > > > --- a/Documentation/admin-guide/kernel-parameters.txt > > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > > @@ -1377,12 +1377,27 @@ Kernel parameters > > > it becomes active and is searched during signature > > > verification. > > > > > > - driver_async_probe= [KNL] > > > - List of driver names to be probed asynchronously. * > > > - matches with all driver names. If * is specified, the > > > - rest of the listed driver names are those that will NOT > > > - match the *. > > > - Format: ,... > > > > You can not remove an existing user/kernel api, sorry, that is not > > allowed as you just broke all systems that were relying on this :( > > > Could you provide more suggestions on how to improve this patch? Not really, sorry, I don't think this is a change that should be done at all. disk naming is a long-solved issue, to think that you can fix that by doing sync/async device probing is not understanding both the issues involved, and how we solved it already :) Hint, never count on block device, or any device, names to be the same across reboots. That has NEVER been guaranteed on systems built in the past 20+ years. Please, just use the existing solutions, no new command line option should ever be needed here. thanks, greg k-h