From d8bbeb39fbf3ff06b6adae9d336f44bee4e3f3ec Mon Sep 17 00:00:00 2001
From: Joao Pinto <Joao.Pinto@synopsys.com>
Date: Wed, 17 Aug 2016 13:26:07 -0500
Subject: [PATCH] PCI: designware: Wait for iATU enable
Add a loop with timeout to make sure the iATU is really enabled before
subsequent config and I/O accesses.
[bhelgaas: split to separate patch, use dev_err() instead of dev_dbg()]
Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/host/pcie-designware.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index e99f56ecd61d..947fac37cf1b 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -31,7 +31,12 @@
#define LINK_WAIT_USLEEP_MIN 90000
#define LINK_WAIT_USLEEP_MAX 100000
-/* Synopsis specific PCIE configuration registers */
+/* Parameters for the waiting for iATU enabled routine */
+#define LINK_WAIT_MAX_IATU_RETRIES 5
+#define LINK_WAIT_IATU_MIN 9000
+#define LINK_WAIT_IATU_MAX 10000
+
+/* Synopsys-specific PCIe configuration registers */
#define PCIE_PORT_LINK_CONTROL 0x710
#define PORT_LINK_MODE_MASK (0x3f << 16)
#define PORT_LINK_MODE_1_LANES (0x1 << 16)
@@ -157,7 +162,7 @@ static int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size,
static void dw_pcie_prog_outbound_atu(struct pcie_port *pp, int index,
int type, u64 cpu_addr, u64 pci_addr, u32 size)
{
- u32 val;
+ u32 retries, val;
dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | index,
PCIE_ATU_VIEWPORT);
@@ -174,7 +179,14 @@ static void dw_pcie_prog_outbound_atu(struct pcie_port *pp, int index,
* Make sure ATU enable takes effect before any subsequent config
* and I/O accesses.
*/
- val = dw_pcie_readl_rc(pp, PCIE_ATU_CR2);
+ for (retries = 0; retries < LINK_WAIT_MAX_IATU_RETRIES; retries++) {
+ val = dw_pcie_readl_rc(pp, PCIE_ATU_CR2);
+ if (val == PCIE_ATU_ENABLE)
+ return;
+
+ usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+ }
+ dev_err(pp->dev, "iATU is not being enabled\n");
}
static struct irq_chip dw_msi_irq_chip = {
--
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