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authorHeiner Kallweit <hkallweit1@gmail.com>2021-09-05 17:59:42 +0200
committerWolfram Sang <wsa@kernel.org>2021-09-29 22:12:44 +0200
commit7d6b61c394a42b8385858bb9e306d48a0112823c (patch)
tree7e20cf7e6f7962a706edd195bbc6a1dc675e30c3 /drivers/i2c/busses
parenti2c: i801: Improve i801_add_mux (diff)
downloadlinux-7d6b61c394a42b8385858bb9e306d48a0112823c.tar.xz
linux-7d6b61c394a42b8385858bb9e306d48a0112823c.zip
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 <andriy.shevchenko@intel.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c/busses')
-rw-r--r--drivers/i2c/busses/i2c-i801.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 6e9aca81b7f0..260fc41b5ca7 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)