[PATCH net-next] net: mana: Reduce waiting time if HWC not responding

[PATCH net-next] net: mana: Reduce waiting time if HWC not responding

[Haiyang Zhang]

From: Haiyang Zhang <haiyangz@microsoft.com>

If HW Channel (HWC) is not responding, reduce the waiting time, so further
steps will fail quickly.
This will prevent getting stuck for a long time (30 minutes or more), for
example, during unloading while HWC is not responding.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/hw_channel.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index ef072e24c46d..ada6c78a2bef 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
@@ -881,7 +881,12 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
 	if (!wait_for_completion_timeout(&ctx->comp_event,
 					 (msecs_to_jiffies(hwc->hwc_timeout)))) {
 		if (hwc->hwc_timeout != 0)
-			dev_err(hwc->dev, "HWC: Request timed out!\n");
+			dev_err(hwc->dev, "HWC: Request timed out: %u ms\n",
+				hwc->hwc_timeout);
+
+		/* Reduce further waiting if HWC no response */
+		if (hwc->hwc_timeout > 1)
+			hwc->hwc_timeout = 1;
 
 		err = -ETIMEDOUT;
 		goto out;
-- 
2.34.1

Re: [PATCH net-next] net: mana: Reduce waiting time if HWC not responding

[Simon Horman]

On Wed, Sep 10, 2025 at 01:57:21PM -0700, Haiyang Zhang wrote:
> From: Haiyang Zhang <haiyangz@microsoft.com>
> 
> If HW Channel (HWC) is not responding, reduce the waiting time, so further
> steps will fail quickly.
> This will prevent getting stuck for a long time (30 minutes or more), for
> example, during unloading while HWC is not responding.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> ---
>  drivers/net/ethernet/microsoft/mana/hw_channel.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
> index ef072e24c46d..ada6c78a2bef 100644
> --- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
> +++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
> @@ -881,7 +881,12 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
>  	if (!wait_for_completion_timeout(&ctx->comp_event,
>  					 (msecs_to_jiffies(hwc->hwc_timeout)))) {
>  		if (hwc->hwc_timeout != 0)
> -			dev_err(hwc->dev, "HWC: Request timed out!\n");
> +			dev_err(hwc->dev, "HWC: Request timed out: %u ms\n",
> +				hwc->hwc_timeout);
> +
> +		/* Reduce further waiting if HWC no response */
> +		if (hwc->hwc_timeout > 1)
> +			hwc->hwc_timeout = 1;

Hi,

Perhaps it is already the case, but I'm wondering if the configured
value of hwc_timeout should be restored at some point.

>  
>  		err = -ETIMEDOUT;
>  		goto out;
> -- 
> 2.34.1
> 
> 

RE: [EXTERNAL] Re: [PATCH net-next] net: mana: Reduce waiting time if HWC not responding

[Haiyang Zhang]

> -----Original Message-----
> From: Simon Horman <horms@kernel.org>
> Sent: Friday, September 12, 2025 8:29 AM
> To: Haiyang Zhang <haiyangz@linux.microsoft.com>
> Cc: linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; Haiyang Zhang
> <haiyangz@microsoft.com>; Dexuan Cui <decui@microsoft.com>; KY Srinivasan
> <kys@microsoft.com>; wei.liu@kernel.org; edumazet@google.com;
> davem@davemloft.net; kuba@kernel.org; pabeni@redhat.com; Long Li
> <longli@microsoft.com>; ssengar@linux.microsoft.com;
> ernis@linux.microsoft.com; dipayanroy@linux.microsoft.com; Konstantin
> Taranov <kotaranov@microsoft.com>; Shiraz Saleem
> <shirazsaleem@microsoft.com>; andrew+netdev@lunn.ch; linux-
> kernel@vger.kernel.org
> Subject: [EXTERNAL] Re: [PATCH net-next] net: mana: Reduce waiting time if
> HWC not responding
> 
> On Wed, Sep 10, 2025 at 01:57:21PM -0700, Haiyang Zhang wrote:
> > From: Haiyang Zhang <haiyangz@microsoft.com>
> >
> > If HW Channel (HWC) is not responding, reduce the waiting time, so
> further
> > steps will fail quickly.
> > This will prevent getting stuck for a long time (30 minutes or more),
> for
> > example, during unloading while HWC is not responding.
> >
> > Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> > ---
> >  drivers/net/ethernet/microsoft/mana/hw_channel.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c
> b/drivers/net/ethernet/microsoft/mana/hw_channel.c
> > index ef072e24c46d..ada6c78a2bef 100644
> > --- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
> > +++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
> > @@ -881,7 +881,12 @@ int mana_hwc_send_request(struct hw_channel_context
> *hwc, u32 req_len,
> >  	if (!wait_for_completion_timeout(&ctx->comp_event,
> >  					 (msecs_to_jiffies(hwc->hwc_timeout)))) {
> >  		if (hwc->hwc_timeout != 0)
> > -			dev_err(hwc->dev, "HWC: Request timed out!\n");
> > +			dev_err(hwc->dev, "HWC: Request timed out: %u ms\n",
> > +				hwc->hwc_timeout);
> > +
> > +		/* Reduce further waiting if HWC no response */
> > +		if (hwc->hwc_timeout > 1)
> > +			hwc->hwc_timeout = 1;
> 
> Hi,
> 
> Perhaps it is already the case, but I'm wondering if the configured
> value of hwc_timeout should be restored at some point.

Yes it's already the case: when the driver does reset/recovery, or gets
a timeout-value-message from the NIC, the time out value will be updated.

Thanks,
- Haiyang

Re: [PATCH net-next] net: mana: Reduce waiting time if HWC not responding

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 10 Sep 2025 13:57:21 -0700 you wrote:
> From: Haiyang Zhang <haiyangz@microsoft.com>
> 
> If HW Channel (HWC) is not responding, reduce the waiting time, so further
> steps will fail quickly.
> This will prevent getting stuck for a long time (30 minutes or more), for
> example, during unloading while HWC is not responding.
> 
> [...]

Here is the summary with links:
  - [net-next] net: mana: Reduce waiting time if HWC not responding
    https://git.kernel.org/netdev/net-next/c/c4deabbc1abe

You are awesome, thank you!
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