diff options
| author | Alex Elder <elder@linaro.org> | 2021-11-24 13:44:15 -0600 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-11-25 20:03:20 -0800 |
| commit | 4c9d631adbc277b33704a971cde6dd8ce44fbb8f (patch) | |
| tree | 14c6ca62b0a80db6f5be734314a553c62b3e450f /drivers/net/ipa/gsi.h | |
| parent | 8e25fa5af89a54ad258ba90a17c90f9fc2b8c523 (diff) | |
| download | linux-4c9d631adbc277b33704a971cde6dd8ce44fbb8f.tar.bz2 | |
net: ipa: introduce channel flow control
One quirk for certain versions of IPA is that endpoint DELAY mode
does not work properly. IPA DELAY mode prevents any packets from
being delivered to the IPA core for processing on a TX endpoint.
The AP uses DELAY mode when the modem crashes, to prevent modem TX
endpoints from generating traffic during crash recovery. Without
this, there is a chance the hardware will stall during recovery from
a modem crash.
To achieve a similar effect, a GSI FLOW_CONTROLLED channel state
was created. A STARTED TX channel can be placed in FLOW_CONTROLLED
state, which prevents the transfer of any more packets. A channel
in FLOW_CONTROLLED state can be either returned to STARTED state, or
can be transitioned to STOPPED state.
Because this operates on GSI channels, two generic commands were
added to allow the AP to control this state for modem channels
(similar to the ALLOCATE and HALT channel commands).
Previously the code assumed this quirk only applied to IPA v4.2.
In fact, channel flow control (rather than endpoint DELAY mode)
should be used for all versions *starting* with IPA v4.2.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ipa/gsi.h')
| -rw-r--r-- | drivers/net/ipa/gsi.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h index 75dfc7655f3b..1af6266683e2 100644 --- a/drivers/net/ipa/gsi.h +++ b/drivers/net/ipa/gsi.h @@ -101,6 +101,7 @@ enum gsi_channel_state { GSI_CHANNEL_STATE_STARTED = 0x2, GSI_CHANNEL_STATE_STOPPED = 0x3, GSI_CHANNEL_STATE_STOP_IN_PROC = 0x4, + GSI_CHANNEL_STATE_FLOW_CONTROLLED = 0x5, /* IPA v4.2+ */ GSI_CHANNEL_STATE_ERROR = 0xf, }; @@ -216,6 +217,15 @@ int gsi_channel_start(struct gsi *gsi, u32 channel_id); int gsi_channel_stop(struct gsi *gsi, u32 channel_id); /** + * gsi_modem_channel_flow_control() - Set channel flow control state (IPA v4.2+) + * @gsi: GSI pointer returned by gsi_setup() + * @channel_id: Modem TX channel to control + * @enable: Whether to enable flow control (i.e., prevent flow) + */ +void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id, + bool enable); + +/** * gsi_channel_reset() - Reset an allocated GSI channel * @gsi: GSI pointer * @channel_id: Channel to be reset |