From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Mayurkumar Patel To: helgaas@kernel.org, bhelgaas@google.com Cc: rajatja@google.com, linux-pci@vger.kernel.org, andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com, rafael.j.wysocki@intel.com, luis.antonio.tarazona-duarte@intel.com, keith.busch@intel.com, mayurkumar.patel@intel.com Subject: [PATCH v1 1/2] PCI: pciehp: Fix presence detect change interrupt handling Date: Thu, 18 Aug 2016 23:07:58 +0200 Message-Id: <1471554479-42083-1-git-send-email-mayurkumar.patel@intel.com> In-Reply-To: <92EBB4272BF81E4089A7126EC1E7B28466597350@IRSMSX101.ger.corp.intel.com> References: <92EBB4272BF81E4089A7126EC1E7B28466597350@IRSMSX101.ger.corp.intel.com> List-ID: Currently, if very fast hotplug removal and insertion event comes as following [ 608.823412] pciehp 0000:00:1c.1:pcie04: Card not present on Slot(1) [ 608.835249] pciehp 0000:00:1c.1:pcie04: Card present on Slot(1) In this case following scenario happens, While removal: pcie_isr() -> pciehp_queue_interrupt_event() -> triggers queue_work(). work invokes interrupt_event_handler() -> case INT_PRESENCE_OFF and calls handle_surprise_event(). handle_surprise_event() again calls pciehp_get_adapter_status() and reads slot status which might have been changed already due to PCI_EXP_SLTSTA_PDC event for hotplug insertion has happened. So it queues, ENABLE_REQ for both removal and insertion interrupt based on latest slot status. In this case, PCIe device can not be hot-add again because it was never removed due to which device can not get enabled. handle_surprise_event() can be removed and pciehp_queue_power_work() can be directly triggered based on INT_PRESENCE_ON and INT_PRESENCE_OFF from the switch case exist in interrupt_event_hanlder(). The patch ensures the pciehp_queue_power_work() processes presence detect change for removal and insertion correctly. Signed-off-by: Mayurkumar Patel Acked-by: Rajat Jain --- drivers/pci/hotplug/pciehp_ctrl.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 880978b..87c5bea 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -301,20 +301,6 @@ static void handle_button_press_event(struct slot *p_slot) /* * Note: This function must be called with slot->lock held */ -static void handle_surprise_event(struct slot *p_slot) -{ - u8 getstatus; - - pciehp_get_adapter_status(p_slot, &getstatus); - if (!getstatus) - pciehp_queue_power_work(p_slot, DISABLE_REQ); - else - pciehp_queue_power_work(p_slot, ENABLE_REQ); -} - -/* - * Note: This function must be called with slot->lock held - */ static void handle_link_event(struct slot *p_slot, u32 event) { struct controller *ctrl = p_slot->ctrl; @@ -377,14 +363,14 @@ static void interrupt_event_handler(struct work_struct *work) pciehp_green_led_off(p_slot); break; case INT_PRESENCE_ON: - handle_surprise_event(p_slot); + pciehp_queue_power_work(p_slot, ENABLE_REQ); break; case INT_PRESENCE_OFF: /* * Regardless of surprise capability, we need to * definitely remove a card that has been pulled out! */ - handle_surprise_event(p_slot); + pciehp_queue_power_work(p_slot, DISABLE_REQ); break; case INT_LINK_UP: case INT_LINK_DOWN: -- 1.7.9.5