Shin'ichiro Kawasaki 847e1eb30e platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe ... commit 5913320eb0 upstream. p2sb_bar() unhides P2SB device to get resources from the device. It guards the operation by locking pci_rescan_remove_lock so that parallel rescans do not find the P2SB device. However, this lock causes deadlock when PCI bus rescan is triggered by /sys/bus/pci/rescan. The rescan locks pci_rescan_remove_lock and probes PCI devices. When PCI devices call p2sb_bar() during probe, it locks pci_rescan_remove_lock again. Hence the deadlock. To avoid the deadlock, do not lock pci_rescan_remove_lock in p2sb_bar(). Instead, do the lock at fs_initcall. Introduce p2sb_cache_resources() for fs_initcall which gets and caches the P2SB resources. At p2sb_bar(), refer the cache and return to the caller. Before operating the device at P2SB DEVFN for resource cache, check that its device class is PCI_CLASS_MEMORY_OTHER 0x0580 that PCH specifications define. This avoids unexpected operation to other devices at the same DEVFN. Link: https://lore.kernel.org/linux-pci/6xb24fjmptxxn5js2fjrrddjae6twex5bjaftwqsuawuqqqydx@7cl3uik5ef6j/ Fixes: 9745fb0747 ("platform/x86/intel: Add Primary to Sideband (P2SB) bridge support") Cc: stable@vger.kernel.org Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20240108062059.3583028-2-shinichiro.kawasaki@wdc.com Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by Klara Modin <klarasmodin@gmail.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-01-31 16:19:07 -08:00
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chrome	platform/chrome: kunit: initialize lock for fake ec_dev	2023-11-28 17:19:39 +00:00
goldfish
loongarch
mellanox	platform/mellanox: Check devm_hwmon_device_register_with_groups() return value	2023-12-13 18:45:05 +01:00
mips
olpc	platform/olpc: olpc-xo175-ec: Use SPI device ID data to bind device	2023-03-20 14:43:35 +01:00
surface	platform/surface: aggregator: fix recv_buf() return value	2023-12-13 18:45:24 +01:00
x86	platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe	2024-01-31 16:19:07 -08:00
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