From:   Alex Elder <elder@linaro.org>
To:     davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com
Cc:     caleb.connolly@linaro.org, mka@chromium.org, evgreen@chromium.org,
        andersson@kernel.org, quic_cpratapa@quicinc.com,
        quic_avuyyuru@quicinc.com, quic_jponduru@quicinc.com,
        quic_subashab@quicinc.com, elder@kernel.org,
        netdev@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net-next 1/6] net: ipa: fix an incorrect assignment
Date:   Wed, 15 Feb 2023 13:53:47 -0600
Message-Id: <20230215195352.755744-2-elder@linaro.org>
In-Reply-To: <20230215195352.755744-1-elder@linaro.org>
References: <20230215195352.755744-1-elder@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

I spotted an error in a patch posted this week, unfortunately just
after it got accepted.  The effect of the bug is that time-based
interrupt moderation is disabled.  This is not technically a bug,
but it is not what is intended.  The problem is that a |= assignment
got implemented as a simple assignment, so the previously assigned
value was ignored.

Fixes: edc6158b18af ("net: ipa: define fields for event-ring related registers")
Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index f44d2d843de12..05ea2502201da 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -762,7 +762,7 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id)
 	/* Enable interrupt moderation by setting the moderation delay */
 	reg = gsi_reg(gsi, EV_CH_E_CNTXT_8);
 	val = reg_encode(reg, EV_MODT, GSI_EVT_RING_INT_MODT);
-	val = reg_encode(reg, EV_MODC, 1);	/* comes from channel */
+	val |= reg_encode(reg, EV_MODC, 1);	/* comes from channel */
 	/* EV_MOD_CNT is 0 (no counter-based interrupt coalescing) */
 	iowrite32(val, gsi->virt + reg_n_offset(reg, evt_ring_id));
 
-- 
2.34.1