[PATCH net 0/2] mlxsw: Couple of fixes

[PATCH net 0/2] mlxsw: Couple of fixes

[Ido Schimmel]

From: Ido Schimmel <idosch@nvidia.com>

This patch set contains two fixes for mlxsw.

Patch #1 fixes firmware flashing when CONFIG_MLXSW_CORE=y and
CONFIG_MLXFW=m.

Patch #2 prevents EMAD transactions from needlessly failing when the
system is under heavy load by using exponential backoff.

Please consider patch #2 for stable.

Ido Schimmel (2):
  mlxsw: Fix firmware flashing
  mlxsw: core: Use variable timeout for EMAD retries

 drivers/net/ethernet/mellanox/mlxsw/Kconfig | 2 +-
 drivers/net/ethernet/mellanox/mlxsw/core.c  | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

-- 
2.28.0

[PATCH net 1/2] mlxsw: Fix firmware flashing

[Ido Schimmel]

From: Ido Schimmel <idosch@nvidia.com>

The commit cited below moved firmware flashing functionality from
mlxsw_spectrum to mlxsw_core, but did not adjust the Kconfig
dependencies. This makes it possible to have mlxsw_core as built-in and
mlxfw as a module. The mlxfw code is therefore not reachable from
mlxsw_core and firmware flashing fails:

# devlink dev flash pci/0000:01:00.0 file mellanox/mlxsw_spectrum-13.2008.1310.mfa2
devlink answers: Operation not supported

Fix by having mlxsw_core select mlxfw.

Fixes: b79cb787ac70 ("mlxsw: Move fw flashing code into core.c")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reported-by: Vadim Pasternak <vadimp@nvidia.com>
Tested-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/Kconfig b/drivers/net/ethernet/mellanox/mlxsw/Kconfig
index 872e9910bb7c..a619d90559f7 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/Kconfig
+++ b/drivers/net/ethernet/mellanox/mlxsw/Kconfig
@@ -6,6 +6,7 @@
 config MLXSW_CORE
 	tristate "Mellanox Technologies Switch ASICs support"
 	select NET_DEVLINK
+	select MLXFW
 	help
 	  This driver supports Mellanox Technologies Switch ASICs family.
 
@@ -82,7 +83,6 @@ config MLXSW_SPECTRUM
 	select GENERIC_ALLOCATOR
 	select PARMAN
 	select OBJAGG
-	select MLXFW
 	imply PTP_1588_CLOCK
 	select NET_PTP_CLASSIFY if PTP_1588_CLOCK
 	default m
-- 
2.28.0

[PATCH net 2/2] mlxsw: core: Use variable timeout for EMAD retries

[Ido Schimmel]

From: Ido Schimmel <idosch@nvidia.com>

The driver sends Ethernet Management Datagram (EMAD) packets to the
device for configuration purposes and waits for up to 200ms for a reply.
A request is retried up to 5 times.

When the system is under heavy load, replies are not always processed in
time and EMAD transactions fail.

Make the process more robust to such delays by using exponential
backoff. First wait for up to 200ms, then retransmit and wait for up to
400ms and so on.

Fixes: caf7297e7ab5 ("mlxsw: core: Introduce support for asynchronous EMAD register access")
Reported-by: Denis Yulevich <denisyu@nvidia.com>
Tested-by: Denis Yulevich <denisyu@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 937b8e46f8c7..1a86535c4968 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -571,7 +571,8 @@ static void mlxsw_emad_trans_timeout_schedule(struct mlxsw_reg_trans *trans)
 	if (trans->core->fw_flash_in_progress)
 		timeout = msecs_to_jiffies(MLXSW_EMAD_TIMEOUT_DURING_FW_FLASH_MS);
 
-	queue_delayed_work(trans->core->emad_wq, &trans->timeout_dw, timeout);
+	queue_delayed_work(trans->core->emad_wq, &trans->timeout_dw,
+			   timeout << trans->retries);
 }
 
 static int mlxsw_emad_transmit(struct mlxsw_core *mlxsw_core,
-- 
2.28.0

Re: [PATCH net 0/2] mlxsw: Couple of fixes

[Jakub Kicinski]

On Tue, 17 Nov 2020 19:33:50 +0200 Ido Schimmel wrote:
> This patch set contains two fixes for mlxsw.
> 
> Patch #1 fixes firmware flashing when CONFIG_MLXSW_CORE=y and
> CONFIG_MLXFW=m.
> 
> Patch #2 prevents EMAD transactions from needlessly failing when the
> system is under heavy load by using exponential backoff.
> 
> Please consider patch #2 for stable.

Applied, and queued, thanks!