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

From: Alex Elder
Date: Wed Nov 25 2020 - 15:45:47 EST


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@xxxxxxxxxx>
---
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