From 651fb94aaf245430590216d497fb8b02dd73d5f9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= Date: Mon, 6 Jul 2026 17:54:23 +0000 Subject: [PATCH] alpha/PCI: Fix I/O port accessor argument order in pci_legacy_write() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit pci_legacy_write() in arch/alpha/kernel/pci-sysfs.c passes its arguments to outb(), outw() and outl() in the wrong order: outb(port, val); The Alpha I/O accessors in arch/alpha/include/asm/io.h take the value first and the port second: extern void outb(u8 b, unsigned long port); So the port number is written as data to the I/O address taken from the user-supplied value, and the intended write to the requested port never happens. The arguments have been reversed since the file was added, and the function returns the access size regardless, so the caller sees success while the requested port is left untouched. Fixes: 10a0ef39fbd1 ("PCI/alpha: pci sysfs resources") Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Tested-by: Magnus Lindholm Reviewed-by: Magnus Lindholm Acked-by: Magnus Lindholm Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260706175423.98305-1-kwilczynski@kernel.org --- arch/alpha/kernel/pci-sysfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c index 94dbc470cd6c..7050f0f7fe3d 100644 --- a/arch/alpha/kernel/pci-sysfs.c +++ b/arch/alpha/kernel/pci-sysfs.c @@ -224,17 +224,17 @@ int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size) switch(size) { case 1: - outb(port, val); + outb(val, port); return 1; case 2: if (port & 1) return -EINVAL; - outw(port, val); + outw(val, port); return 2; case 4: if (port & 3) return -EINVAL; - outl(port, val); + outl(val, port); return 4; } return -EINVAL;