[PATCH net-next 2/2] net: ipa: only reset channel twice for IPA v3.5.1

From: Alex Elder
Date: Mon May 04 2020 - 19:30:30 EST


In gsi_channel_reset(), RX channels are subjected to two consecutive
CHANNEL_RESET commands. This workaround should only be used for IPA
version 3.5.1, and for newer hardware "can lead to unwanted behavior."

Only issue the second CHANNEL_RESET command for legacy hardware.

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

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index cd5d8045c7e5..8ccbbb920c11 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -840,9 +840,9 @@ void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool legacy)

mutex_lock(&gsi->mutex);

- /* Due to a hardware quirk we need to reset RX channels twice. */
gsi_channel_reset_command(channel);
- if (!channel->toward_ipa)
+ /* Due to a hardware quirk we may need to reset RX channels twice. */
+ if (legacy && !channel->toward_ipa)
gsi_channel_reset_command(channel);

gsi_channel_program(channel, legacy);
--
2.20.1