]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
PCI: rcar-host: Drop PMSR spinlock
authorMarek Vasut <marek.vasut+renesas@mailbox.org>
Tue, 21 Oct 2025 18:46:28 +0000 (14:46 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 29 Oct 2025 13:03:15 +0000 (14:03 +0100)
commit61d6249ea441be3d45666404dd2e8bdcf7251ead
tree658a06fc1c90739a82e6d68f5ac18839ca5c96ed
parent9e14fb714ebf55443dd3449de9ea2ffcf13e562a
PCI: rcar-host: Drop PMSR spinlock

[ Upstream commit 0a8f173d9dad13930d5888505dc4c4fd6a1d4262 ]

The pmsr_lock spinlock used to be necessary to synchronize access to the
PMSR register, because that access could have been triggered from either
config space access in rcar_pcie_config_access() or an exception handler
rcar_pcie_aarch32_abort_handler().

The rcar_pcie_aarch32_abort_handler() case is no longer applicable since
commit 6e36203bc14c ("PCI: rcar: Use PCI_SET_ERROR_RESPONSE after read
which triggered an exception"), which performs more accurate, controlled
invocation of the exception, and a fixup.

This leaves rcar_pcie_config_access() as the only call site from which
rcar_pcie_wakeup() is called. The rcar_pcie_config_access() can only be
called from the controller struct pci_ops .read and .write callbacks,
and those are serialized in drivers/pci/access.c using raw spinlock
'pci_lock' . It should be noted that CONFIG_PCI_LOCKLESS_CONFIG is never
set on this platform.

Since the 'pci_lock' is a raw spinlock , and the 'pmsr_lock' is not a
raw spinlock, this constellation triggers 'BUG: Invalid wait context'
with CONFIG_PROVE_RAW_LOCK_NESTING=y .

Remove the pmsr_lock to fix the locking.

Fixes: a115b1bd3af0 ("PCI: rcar: Add L1 link state fix into data abort hook")
Reported-by: Duy Nguyen <duy.nguyen.rh@renesas.com>
Reported-by: Thuan Nguyen <thuan.nguyen-hong@banvien.com.vn>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250909162707.13927-1-marek.vasut+renesas@mailbox.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/pci/controller/pcie-rcar-host.c