[PATCH net-next 1/6] net: ipa: reverse logic on escape buffer use

From: Alex Elder <elder@linaro.org>
To: davem@davemloft.net, kuba@kernel.org
Cc: evgreen@chromium.org, subashab@codeaurora.org,
	cpratapa@codeaurora.org, bjorn.andersson@linaro.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net-next 1/6] net: ipa: reverse logic on escape buffer use
Date: Wed, 25 Nov 2020 14:45:17 -0600	[thread overview]
Message-ID: <20201125204522.5884-2-elder@linaro.org> (raw)
In-Reply-To: <20201125204522.5884-1-elder@linaro.org>

Starting with IPA v4.2 there is a GSI channel option to use an
"escape buffer" instead of prefetch buffers.  This should be used
for all channels *except* the AP command TX channel.  The logic
that implements this has it backwards; fix this bug.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index eb4c5d408a835..2cf10c9f0143d 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -781,8 +781,10 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell)
 	if (gsi->version == IPA_VERSION_3_5_1 && doorbell)
 		val |= USE_DB_ENG_FMASK;
 
-	/* Starting with IPA v4.0 the command channel uses the escape buffer */
-	if (gsi->version != IPA_VERSION_3_5_1 && channel->command)
+	/* v4.0 introduces an escape buffer for prefetch.  We use it
+	 * on all but the AP command channel.
+	 */
+	if (gsi->version != IPA_VERSION_3_5_1 && !channel->command)
 		val |= USE_ESCAPE_BUF_ONLY_FMASK;
 
 	iowrite32(val, gsi->virt + GSI_CH_C_QOS_OFFSET(channel_id));
-- 
2.20.1

