[PATCH v2 2/7] PCI: intel-gw: Move interrupt enable to own function

[Florian Eckert <fe@dev.tdt.de>]

To improve the readability of the code, move the interrupt enable
instructions to a separate function. That is already done for the disable
interrupt instruction.

In addtion, all pending interrupts are cleared and disabled, just as this
is done in the disable function 'intel_pcie_core_irq_disable()'. After
that, all relevant interrupts are enabled again. The 'PCIE_APP_IRNEN'
definition contains all the relevant interrupts that are of interest.

This change is also done in the Maxlinear SDK [1]. As I unfortunately
don’t have any documentation for this IP core, I suspect that the
intention is to set the IP core for interrupt handling to a specific
state. Perhaps the problem was that the IP core did not reinitialize the
interrupt register properly after a power cycle.

In my view, it can’t do any harm to switch the interrupt off and then on
again to set them to a specific state.

[1] https://github.com/maxlinear/linux/blob/updk_9.1.90/drivers/pci/controller/dwc/pcie-intel-gw.c#L431

Signed-off-by: Florian Eckert <fe@dev.tdt.de>
---
 drivers/pci/controller/dwc/pcie-intel-gw.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-intel-gw.c b/drivers/pci/controller/dwc/pcie-intel-gw.c
index 80d1607c46cbbb1e274b37a0bb9377a877678f5d..e88b8243cc41c607c39e4d58c4dcd8c8c082e8b0 100644
--- a/drivers/pci/controller/dwc/pcie-intel-gw.c
+++ b/drivers/pci/controller/dwc/pcie-intel-gw.c
@@ -195,6 +195,13 @@ static void intel_pcie_device_rst_deassert(struct intel_pcie *pcie)
 	gpiod_set_value_cansleep(pcie->reset_gpio, 0);
 }
 
+static void intel_pcie_core_irq_enable(struct intel_pcie *pcie)
+{
+	pcie_app_wr(pcie, PCIE_APP_IRNEN, 0);
+	pcie_app_wr(pcie, PCIE_APP_IRNCR, PCIE_APP_IRN_INT);
+	pcie_app_wr(pcie, PCIE_APP_IRNEN, PCIE_APP_IRN_INT);
+}
+
 static void intel_pcie_core_irq_disable(struct intel_pcie *pcie)
 {
 	pcie_app_wr(pcie, PCIE_APP_IRNEN, 0);
@@ -316,9 +323,7 @@ static int intel_pcie_host_setup(struct intel_pcie *pcie)
 	if (ret)
 		goto app_init_err;
 
-	/* Enable integrated interrupts */
-	pcie_app_wr_mask(pcie, PCIE_APP_IRNEN, PCIE_APP_IRN_INT,
-			 PCIE_APP_IRN_INT);
+	intel_pcie_core_irq_enable(pcie);
 
 	return 0;
 

-- 
2.47.3