[PATCH 5.4 185/191] bnxt: apply computed clamp value for coalece parameter

Greg Kroah-Hartman
2020-01-02T22:56:22Z

From: Jonathan Lemon <jonathan.lemon@gmail.com>

[ Upstream commit 6adc4601c2a1ac87b4ab8ed0cb55db6efd0264e8 ]

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>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6178,7 +6178,7 @@ static void bnxt_hwrm_set_coal_params(st
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);
}