[PATCH 3/4] PCI/hotplug: reset_lock is not required synchronizing with irq thread

Ilpo Järvinen
2025-03-13T14:24:21Z

Disabling HPIE (Hot-Plug Interrupt Enable) and synchronizing with irq
handling in pciehp_reset_slot() is enough to ensure no pending events
are processed during the slot reset. Thus, there is no need to take
reset_lock in the IRQ thread.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
drivers/pci/hotplug/pciehp_hpc.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 634cf5004f76..26150a6b48f4 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -748,12 +748,10 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
* Disable requests have higher priority than Presence Detect Changed
* or Data Link Layer State Changed events.
*/
- down_read_nested(&ctrl->reset_lock, ctrl->depth);
if (events & DISABLE_SLOT)
pciehp_handle_disable_request(ctrl);
else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC))
pciehp_handle_presence_or_link_change(ctrl, events);
- up_read(&ctrl->reset_lock);

ret = IRQ_HANDLED;
out:
--
2.39.5