From f8d46c89c86fa11c60c05e101a3a4c7458623103 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Wed, 20 Jun 2018 15:38:27 -0600 Subject: [PATCH] PCI/DPC: Leave interrupts enabled while handling event Now that the DPC driver clears the interrupt status before exiting the IRQ handler, we don't need to abuse the DPC control register to know if a shared interrupt is for a new DPC event: a DPC port can not trigger a second interrupt until the host clears the trigger status later in the work queue handler. Signed-off-by: Keith Busch Signed-off-by: Bjorn Helgaas Reviewed-by: Sinan Kaya Reviewed-by: Oza Pawandeep --- drivers/pci/pcie/dpc.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-) diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index 921ed979109da..972aac8928462 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -77,7 +77,7 @@ static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) struct dpc_dev *dpc; struct pcie_device *pciedev; struct device *devdpc; - u16 cap, ctl; + u16 cap; /* * DPC disables the Link automatically in hardware, so it has @@ -105,10 +105,6 @@ static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_TRIGGER); - pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl); - pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL, - ctl | PCI_EXP_DPC_CTL_INT_EN); - return PCI_ERS_RESULT_RECOVERED; } @@ -183,16 +179,11 @@ static irqreturn_t dpc_irq(int irq, void *context) struct dpc_dev *dpc = (struct dpc_dev *)context; struct pci_dev *pdev = dpc->dev->port; struct device *dev = &dpc->dev->device; - u16 cap = dpc->cap_pos, ctl, status, source, reason, ext_reason; - - pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl); - - if (!(ctl & PCI_EXP_DPC_CTL_INT_EN) || ctl == (u16)(~0)) - return IRQ_NONE; + u16 cap = dpc->cap_pos, status, source, reason, ext_reason; pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); - if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT)) + if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0)) return IRQ_NONE; if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) { @@ -201,9 +192,6 @@ static irqreturn_t dpc_irq(int irq, void *context) return IRQ_HANDLED; } - pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL, - ctl & ~PCI_EXP_DPC_CTL_INT_EN); - pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source); @@ -226,9 +214,8 @@ static irqreturn_t dpc_irq(int irq, void *context) pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_INTERRUPT); - - schedule_work(&dpc->work); - + if (status & PCI_EXP_DPC_STATUS_TRIGGER) + schedule_work(&dpc->work); return IRQ_HANDLED; } -- 2.39.2