From 8e033a93b37f37aa9fca71a370a895155320af60 Mon Sep 17 00:00:00 2001 From: Yuval Mintz Date: Wed, 10 Jan 2018 11:42:43 +0100 Subject: [PATCH] mlxsw: pci: Wait after reset before accessing HW After performing reset driver polls on HW indication until learning that the reset is done, but immediately after reset the device becomes unresponsive which might lead to completion timeout on the first read. Wait for 100ms before starting the polling. Fixes: 233fa44bd67a ("mlxsw: pci: Implement reset done check") Signed-off-by: Yuval Mintz Reviewed-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/pci.c | 7 ++++++- drivers/net/ethernet/mellanox/mlxsw/pci_hw.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c index 23f7d82..6ef20e5 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/pci.c +++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c @@ -1643,7 +1643,12 @@ static int mlxsw_pci_sw_reset(struct mlxsw_pci *mlxsw_pci, return 0; } - wmb(); /* reset needs to be written before we read control register */ + /* Reset needs to be written before we read control register, and + * we must wait for the HW to become responsive once again + */ + wmb(); + msleep(MLXSW_PCI_SW_RESET_WAIT_MSECS); + end = jiffies + msecs_to_jiffies(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS); do { u32 val = mlxsw_pci_read32(mlxsw_pci, FW_READY); diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci_hw.h b/drivers/net/ethernet/mellanox/mlxsw/pci_hw.h index a644120..fb082ad2 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/pci_hw.h +++ b/drivers/net/ethernet/mellanox/mlxsw/pci_hw.h @@ -59,6 +59,7 @@ #define MLXSW_PCI_SW_RESET 0xF0010 #define MLXSW_PCI_SW_RESET_RST_BIT BIT(0) #define MLXSW_PCI_SW_RESET_TIMEOUT_MSECS 5000 +#define MLXSW_PCI_SW_RESET_WAIT_MSECS 100 #define MLXSW_PCI_FW_READY 0xA1844 #define MLXSW_PCI_FW_READY_MASK 0xFFFF #define MLXSW_PCI_FW_READY_MAGIC 0x5E -- 2.7.4