From patchwork Tue May 6 12:51:42 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roxana Nicolescu X-Patchwork-Id: 888479 Received: from mail-4316.protonmail.ch (mail-4316.protonmail.ch [185.70.43.16]) (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 44550280000; Tue, 6 May 2025 12:51:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.70.43.16 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746535910; cv=none; b=Ub5R6jAX0SUAVIazEz1LYyJR8ssRKFp5QfFsxC0m871I6rPrzOUwYIfsdApbvEXkPvXQ7OyhidWmKrwy4XuMolQ8R6xJk0ToRY+3lhwv2Uj2+dCWMWdo5yTPabSa25U2cdc6iWpVJMeh2THJ07V+wQ/dkMFoFsKVLqEaps8ZcBA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746535910; c=relaxed/simple; bh=XwcK4xNdJ5bqnZI9n1Ki4hOFLIohBhzddbgDl9oczSs=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=r+MWdTSaakb9b8gjPQtFuDBnmSdZWkjKM7FfAUmEYjUAADNphSuV6NBziCALLlim7X+q1N9yGKpe+SkqF9BFACrTzfcfTPwseVGO/ptFiPKo44Irw7JRDhocDKzo61FG+W1VG0nfUR/Uy1oUV0JiSEPfGCR8pglU3bWo0lMrVFA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=protonmail.com; spf=pass smtp.mailfrom=protonmail.com; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.b=xriuQwmg; arc=none smtp.client-ip=185.70.43.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=protonmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=protonmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.b="xriuQwmg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1746535907; x=1746795107; bh=XwcK4xNdJ5bqnZI9n1Ki4hOFLIohBhzddbgDl9oczSs=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector:List-Unsubscribe:List-Unsubscribe-Post; b=xriuQwmgfNo5DJYwsgvwXvgfFBiWmCAPaxQdVdukMugEO9rR5CTpY8eU3pRNj1f9x naLNfbifRO65P3pmphcdCQfj01iN+4Nl0BzL3XCzMDveTZTTf2KiQ7WQAXfq6oeH0r VW5A9adatchp3fDbcA59DQeQkLrWtaWzBcO1incMCbLxhDtvmopzRobokwGufC7sn+ W6SvnuXs0Nj4vGf78CECa5asUyKLXZri45ydxvnOeRdcVTvhLb6et67k4SsgqBimgl aM8a2Wf0WxrrlKy35DnJCNnlzoM8M1qpgPDUhulOq36d6LRBRBUvdWA5gejYMuYv4G CPwtRcrehi+fQ== Date: Tue, 06 May 2025 12:51:42 +0000 To: gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, jason.wessel@windriver.com, danielt@kernel.org, dianders@chromium.org, jirislaby@kernel.org From: Roxana Nicolescu Cc: kgdb-bugreport@lists.sourceforge.net, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev Subject: [RFC PATCH 1/2] driver core: faux: create the device if probe() is deferred too Message-ID: <20250506125133.108786-2-nicolescu.roxana@protonmail.com> In-Reply-To: <20250506125133.108786-1-nicolescu.roxana@protonmail.com> References: <20250506125133.108786-1-nicolescu.roxana@protonmail.com> Feedback-ID: 136600343:user:proton X-Pm-Message-ID: 015bbc2fe70bde887f946c07da822d9b7a6c0ae5 Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 There are situations when the faux device is probed, it waits for the availability for another piece of hardware. In case this dependency is not available, it can return -EPROBE_DEFER and probe will be retried later. But, with the current implementation, probe won't be retried at all because we destroyed the faux device in case probe did not return 0 and therefore the device is binded to the driver. To solve this, the faux device creation fails only when probe failed with something other than -EPROBE_DEFER. In order to achieve this, a boolean var is used in struct faux_object. Signed-off-by: Roxana Nicolescu --- drivers/base/faux.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/base/faux.c b/drivers/base/faux.c index 407c1d1aad50..21e385631872 100644 --- a/drivers/base/faux.c +++ b/drivers/base/faux.c @@ -25,6 +25,7 @@ struct faux_object { struct faux_device faux_dev; const struct faux_device_ops *faux_ops; + bool probe_successed_or_deferred; }; #define to_faux_object(dev) container_of_const(dev, struct faux_object, faux_dev.dev) @@ -48,6 +49,8 @@ static int faux_probe(struct device *dev) if (faux_ops && faux_ops->probe) ret = faux_ops->probe(faux_dev); + faux_obj->probe_successed_or_deferred = !ret || ret == -EPROBE_DEFER; + return ret; } @@ -150,12 +153,13 @@ struct faux_device *faux_device_create_with_groups(const char *name, } /* - * Verify that we did bind the driver to the device (i.e. probe worked), + * Verify that we either did bind the driver to the device (i.e. probe worked), + * or probe is deferred and tried later, * if not, let's fail the creation as trying to guess if probe was * successful is almost impossible to determine by the caller. */ - if (!dev->driver) { - dev_err(dev, "probe did not succeed, tearing down the device\n"); + if (!faux_obj->probe_successed_or_deferred) { + dev_err(dev, "probe did not succeed and it's not deferred, tearing down the device\n"); faux_device_destroy(faux_dev); faux_dev = NULL; }