diff mbox

[v3,4/6] PCI: xilinx: Clear interrupt FIFO during probe

Message ID 1454602213-967-5-git-send-email-paul.burton@imgtec.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Paul Burton Feb. 4, 2016, 4:10 p.m. UTC
xilinx_pcie_init_port clears the pending interrupts in the interrupt
decode register, but does not clear the interrupt FIFO. This would lead
to spurious interrupts if any were present in the FIFO at probe time.
Clear the interrupt FIFO prior to the interrupt decode register in order
to start with a clean slate as expected.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 8961def56845 ("PCI: xilinx: Add Xilinx AXI PCIe Host Bridge IP driver")

---

Changes in v3:
- Split out from Boston patchset.

Changes in v2:
- Add Fixes tag.

 drivers/pci/host/pcie-xilinx.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Bharat Kumar Gogada Feb. 11, 2016, 6:20 a.m. UTC | #1
> xilinx_pcie_init_port clears the pending interrupts in the interrupt decode
> register, but does not clear the interrupt FIFO. This would lead to spurious
> interrupts if any were present in the FIFO at probe time.
> Clear the interrupt FIFO prior to the interrupt decode register in order to
> start with a clean slate as expected.
> 
> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> Fixes: 8961def56845 ("PCI: xilinx: Add Xilinx AXI PCIe Host Bridge IP driver")
> 
> ---
> 
> Changes in v3:
> - Split out from Boston patchset.
> 
> Changes in v2:
> - Add Fixes tag.
> 
>  drivers/pci/host/pcie-xilinx.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c index
> 1eb74a2..6c5a503 100644
> --- a/drivers/pci/host/pcie-xilinx.c
> +++ b/drivers/pci/host/pcie-xilinx.c
> @@ -568,6 +568,8 @@ static int xilinx_pcie_init_irq_domain(struct
> xilinx_pcie_port *port)
>   */
>  static void xilinx_pcie_init_port(struct xilinx_pcie_port *port)  {
> +	u32 val;
> +
>  	if (xilinx_pcie_link_is_up(port))
>  		dev_info(port->dev, "PCIe Link is UP\n");
>  	else
> @@ -577,6 +579,17 @@ static void xilinx_pcie_init_port(struct
> xilinx_pcie_port *port)
>  	pcie_write(port, ~XILINX_PCIE_IDR_ALL_MASK,
>  		   XILINX_PCIE_REG_IMR);
> 
> +	/* Clear interrupt FIFO */
> +	while (1) {
> +		val = pcie_read(port, XILINX_PCIE_REG_RPIFR1);
> +
> +		if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID))
> +			break;
> +
> +		pcie_write(port, XILINX_PCIE_RPIFR1_ALL_MASK,
> +			   XILINX_PCIE_REG_RPIFR1);
> +	}
> +
Hi Paul,

This case will create problem with error case, suppose if we have continuous correctable errors on link this will always be while loop.

Bharat
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diff mbox

Patch

diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c
index 1eb74a2..6c5a503 100644
--- a/drivers/pci/host/pcie-xilinx.c
+++ b/drivers/pci/host/pcie-xilinx.c
@@ -568,6 +568,8 @@  static int xilinx_pcie_init_irq_domain(struct xilinx_pcie_port *port)
  */
 static void xilinx_pcie_init_port(struct xilinx_pcie_port *port)
 {
+	u32 val;
+
 	if (xilinx_pcie_link_is_up(port))
 		dev_info(port->dev, "PCIe Link is UP\n");
 	else
@@ -577,6 +579,17 @@  static void xilinx_pcie_init_port(struct xilinx_pcie_port *port)
 	pcie_write(port, ~XILINX_PCIE_IDR_ALL_MASK,
 		   XILINX_PCIE_REG_IMR);
 
+	/* Clear interrupt FIFO */
+	while (1) {
+		val = pcie_read(port, XILINX_PCIE_REG_RPIFR1);
+
+		if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID))
+			break;
+
+		pcie_write(port, XILINX_PCIE_RPIFR1_ALL_MASK,
+			   XILINX_PCIE_REG_RPIFR1);
+	}
+
 	/* Clear pending interrupts */
 	pcie_write(port, pcie_read(port, XILINX_PCIE_REG_IDR) &
 			 XILINX_PCIE_IMR_ALL_MASK,