[PATCH net] bnxt: apply computed clamp value for coalece parameter

[PATCH net] bnxt: apply computed clamp value for coalece parameter

[Jonathan Lemon]

After executing "ethtool -C eth0 rx-usecs-irq 0", the box becomes
unresponsive, likely due to interrupt livelock.  It appears that
a minimum clamp value for the irq timer is computed, but is never
applied.

Fix by applying the corrected clamp value.

Fixes: 74706afa712d ("bnxt_en: Update interrupt coalescing logic.")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 85983f0e3134..38bf38342af9 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6186,7 +6186,7 @@ static void bnxt_hwrm_set_coal_params(struct bnxt *bp,
 		tmr = bnxt_usec_to_coal_tmr(bp, hw_coal->coal_ticks_irq);
 		val = clamp_t(u16, tmr, 1,
 			      coal_cap->cmpl_aggr_dma_tmr_during_int_max);
-		req->cmpl_aggr_dma_tmr_during_int = cpu_to_le16(tmr);
+		req->cmpl_aggr_dma_tmr_during_int = cpu_to_le16(val);
 		req->enables |=
 			cpu_to_le16(BNXT_COAL_CMPL_AGGR_TMR_DURING_INT_ENABLE);
 	}
-- 
2.17.1

Re: [PATCH net] bnxt: apply computed clamp value for coalece parameter

[Michael Chan]

On Tue, Dec 10, 2019 at 8:39 AM Jonathan Lemon <jonathan.lemon@gmail.com> wrote:
>
> After executing "ethtool -C eth0 rx-usecs-irq 0", the box becomes
> unresponsive, likely due to interrupt livelock.  It appears that
> a minimum clamp value for the irq timer is computed, but is never
> applied.
>
> Fix by applying the corrected clamp value.
>
> Fixes: 74706afa712d ("bnxt_en: Update interrupt coalescing logic.")
> Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>

Thanks.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>

Re: [PATCH net] bnxt: apply computed clamp value for coalece parameter

[Jakub Kicinski]

On Tue, 10 Dec 2019 08:39:46 -0800, Jonathan Lemon wrote:
> After executing "ethtool -C eth0 rx-usecs-irq 0", the box becomes
> unresponsive, likely due to interrupt livelock.  It appears that
> a minimum clamp value for the irq timer is computed, but is never
> applied.
> 
> Fix by applying the corrected clamp value.
> 
> Fixes: 74706afa712d ("bnxt_en: Update interrupt coalescing logic.")
> Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>

Applied, and queued for stable, thanks!