@@ -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));
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(-) -- 2.20.1