This is a note to let you know that I've just added the patch titled

mlxsw: pci: Wait after reset before accessing HW

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: mlxsw-pci-wait-after-reset-before-accessing-hw.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Feb 28 16:23:28 CET 2018

From: Yuval Mintz yuvalm@mellanox.com Date: Wed, 10 Jan 2018 11:42:43 +0100 Subject: mlxsw: pci: Wait after reset before accessing HW

From: Yuval Mintz yuvalm@mellanox.com

[ Upstream commit 8e033a93b37f37aa9fca71a370a895155320af60 ]

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 yuvalm@mellanox.com Reviewed-by: Ido Schimmel idosch@mellanox.com Signed-off-by: Jiri Pirko jiri@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlxsw/pci.c | 7 ++++++- drivers/net/ethernet/mellanox/mlxsw/pci_hw.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-)

--- 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 mlx 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); --- 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

Patches currently in stable-queue which might be from yuvalm@mellanox.com are

queue-4.14/mlxsw-pci-wait-after-reset-before-accessing-hw.patch