On 29-Oct-17 3:12 PM, Vidya Sagar wrote: > > > On Saturday 28 October 2017 12:59 AM, Manikanta Maddireddy wrote: >> When there are 32 outstanding writes from AFI to memory, the outstanding >> write counter overflows and indicates that there are "0" outstanding write >> transactions. This outstanding write counter is used to generate IDLE >> signal to dynamically gate the AFI clock. >> >> When memory controller is under heavy load, its possible that write >> completions will come back to AFI after long delay and AFI write counter >> overflows. AFI clock gets gated even when there are outstanding >> transactions towards memory controller resutling in system hang. >> >> Disable dynamic clock gating of AFI clock to avoid system hang. >> >> Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx> >> --- >> drivers/pci/host/pci-tegra.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c >> index 27a8211c48b2..b8cac871712b 100644 >> --- a/drivers/pci/host/pci-tegra.c >> +++ b/drivers/pci/host/pci-tegra.c >> @@ -103,8 +103,9 @@ >> #define AFI_MSI_EN_VEC6 0xa4 >> #define AFI_MSI_EN_VEC7 0xa8 >> -#define AFI_CONFIGURATION 0xac >> -#define AFI_CONFIGURATION_EN_FPCI (1 << 0) >> +#define AFI_CONFIGURATION 0xac >> +#define AFI_CONFIGURATION_EN_FPCI (1 << 0) >> +#define AFI_CONFIGURATION_CLKEN_OVERRIDE (1 << 31) > BIT macro is preferred here. Left shift is used everywhere, so to be inline with that I used same format >> #define AFI_FPCI_ERROR_MASKS 0xb0 >> @@ -1057,9 +1058,10 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie) >> } >> } >> - /* finally enable PCIe */ >> + /* Disable AFI dynamic clock gating and enable PCIe */ >> value = afi_readl(pcie, AFI_CONFIGURATION); >> - value |= AFI_CONFIGURATION_EN_FPCI; >> + value |= (AFI_CONFIGURATION_EN_FPCI | >> + AFI_CONFIGURATION_CLKEN_OVERRIDE); >> afi_writel(pcie, value, AFI_CONFIGURATION); >> value = AFI_INTR_EN_INI_SLVERR | AFI_INTR_EN_INI_DECERR | >
