[PATCH 1/2] PCI: altera: check link status before retrain link

From: Ley Foon Tan
Date: Tue Jun 21 2016 - 04:54:30 EST


Checking for link up status before retrain link.

Note, moves altera_pcie_link_is_up() and its dependency functions
to top of file.

Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx>
---
drivers/pci/host/pcie-altera.c | 36 ++++++++++++++++++++----------------
1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c
index dbac6fb..78f77e1 100644
--- a/drivers/pci/host/pcie-altera.c
+++ b/drivers/pci/host/pcie-altera.c
@@ -81,9 +81,29 @@ struct tlp_rp_regpair_t {
u32 reg1;
};

+static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
+ const u32 reg)
+{
+ writel_relaxed(value, pcie->cra_base + reg);
+}
+
+static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
+{
+ return readl_relaxed(pcie->cra_base + reg);
+}
+
+static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
+{
+ return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
+}
+
static void altera_pcie_retrain(struct pci_dev *dev)
{
u16 linkcap, linkstat;
+ struct altera_pcie *pcie = dev->bus->sysdata;
+
+ if(!altera_pcie_link_is_up(pcie))
+ return;

/*
* Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
@@ -120,17 +140,6 @@ static bool altera_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int devfn,
return false;
}

-static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
- const u32 reg)
-{
- writel_relaxed(value, pcie->cra_base + reg);
-}
-
-static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
-{
- return readl_relaxed(pcie->cra_base + reg);
-}
-
static void tlp_write_tx(struct altera_pcie *pcie,
struct tlp_rp_regpair_t *tlp_rp_regdata)
{
@@ -139,11 +148,6 @@ static void tlp_write_tx(struct altera_pcie *pcie,
cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
}

-static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
-{
- return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
-}
-
static bool altera_pcie_valid_config(struct altera_pcie *pcie,
struct pci_bus *bus, int dev)
{
--
1.8.2.1