From 7d6b61c394a42b8385858bb9e306d48a0112823c Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sun, 5 Sep 2021 17:59:42 +0200 Subject: [PATCH] i2c: i801: Use PCI bus rescan mutex to protect P2SB access As pointed out by Andy in [0] using a local mutex here isn't strictly wrong but not sufficient. We should hold the PCI rescan lock for P2SB operations. [0] https://www.spinics.net/lists/linux-i2c/msg52717.html Fixes: 1a987c69ce2c ("i2c: i801: make p2sb_spinlock a mutex") Reported-by: Andy Shevchenko Signed-off-by: Heiner Kallweit Reviewed-by: Andy Shevchenko Reviewed-by: Jean Delvare Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-i801.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 6e9aca8..260fc41 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -1485,7 +1485,6 @@ static struct platform_device * i801_add_tco_spt(struct i801_priv *priv, struct pci_dev *pci_dev, struct resource *tco_res) { - static DEFINE_MUTEX(p2sb_mutex); struct resource *res; unsigned int devfn; u64 base64_addr; @@ -1498,7 +1497,7 @@ i801_add_tco_spt(struct i801_priv *priv, struct pci_dev *pci_dev, * enumerated by the PCI subsystem, so we need to unhide/hide it * to lookup the P2SB BAR. */ - mutex_lock(&p2sb_mutex); + pci_lock_rescan_remove(); devfn = PCI_DEVFN(PCI_SLOT(pci_dev->devfn), 1); @@ -1516,7 +1515,7 @@ i801_add_tco_spt(struct i801_priv *priv, struct pci_dev *pci_dev, /* Hide the P2SB device, if it was hidden before */ if (hidden) pci_bus_write_config_byte(pci_dev->bus, devfn, 0xe1, hidden); - mutex_unlock(&p2sb_mutex); + pci_unlock_rescan_remove(); res = &tco_res[1]; if (pci_dev->device == PCI_DEVICE_ID_INTEL_DNV_SMBUS) -- 2.7.4