netdev - [PATCH net-next 2/4] ptp: vmclock: Don't unregister misc device if it was not registered

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Message-Id: <20250206-vmclock-probe-v1-2-17a3ea07be34@linutronix.de>
Date: Thu, 06 Feb 2025 18:45:02 +0100
From: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
To: David Woodhouse <dwmw2@...radead.org>, 
 Richard Cochran <richardcochran@...il.com>, 
 Andrew Lunn <andrew+netdev@...n.ch>, 
 "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, 
 Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Cc: David Woodhouse <dwmw@...zon.co.uk>, netdev@...r.kernel.org, 
 linux-kernel@...r.kernel.org, 
 Thomas Weißschuh <thomas.weissschuh@...utronix.de>, 
 stable@...r.kernel.org
Subject: [PATCH net-next 2/4] ptp: vmclock: Don't unregister misc device if
 it was not registered

vmclock_remove() tries to detect the successful registration of the misc
device based on the value of its minor value.
However that check is incorrect if the misc device registration was not
attempted in the first place.

Always initialize the minor number, so the check works properly.

Fixes: 205032724226 ("ptp: Add support for the AMZNC10C 'vmclock' device")
Cc: stable@...r.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
---
 drivers/ptp/ptp_vmclock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ptp/ptp_vmclock.c b/drivers/ptp/ptp_vmclock.c
index 1920698ae6eba6abfff5b61afae1b047910026fd..82e6bef72b1b6edef7d891964c3f9c4546f6ddba 100644
--- a/drivers/ptp/ptp_vmclock.c
+++ b/drivers/ptp/ptp_vmclock.c
@@ -549,6 +549,8 @@ static int vmclock_probe(struct platform_device *pdev)
 		goto out;
 	}

+	st->miscdev.minor = MISC_DYNAMIC_MINOR;
+
 	/*
 	 * If the structure is big enough, it can be mapped to userspace.
 	 * Theoretically a guest OS even using larger pages could still
@@ -556,7 +558,6 @@ static int vmclock_probe(struct platform_device *pdev)
 	 * cross that bridge if/when we come to it.
 	 */
 	if (le32_to_cpu(st->clk->size) >= PAGE_SIZE) {
-		st->miscdev.minor = MISC_DYNAMIC_MINOR;
 		st->miscdev.fops = &vmclock_miscdev_fops;
 		st->miscdev.name = st->name;

-- 
2.48.1