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;a=summary
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@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Feb 28 16:23:28 CET 2018
From: Yuval Mintz <yuvalm@xxxxxxxxxxxx>
Date: Wed, 10 Jan 2018 11:42:43 +0100
Subject: mlxsw: pci: Wait after reset before accessing HW
From: Yuval Mintz <yuvalm@xxxxxxxxxxxx>
[ 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@xxxxxxxxxxxx>
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxxxx>
Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxx are
queue-4.14/mlxsw-pci-wait-after-reset-before-accessing-hw.patch