@@ -860,20 +860,15 @@ static int __gsi_channel_start(struct gsi_channel *channel, bool start)
struct gsi *gsi = channel->gsi;
int ret;
- napi_enable(&channel->napi);
- gsi_irq_ieob_enable_one(gsi, channel->evt_ring_id);
+ if (!start)
+ return 0;
mutex_lock(&gsi->mutex);
- ret = start ? gsi_channel_start_command(channel) : 0;
+ ret = gsi_channel_start_command(channel);
mutex_unlock(&gsi->mutex);
- if (ret) {
- gsi_irq_ieob_disable_one(gsi, channel->evt_ring_id);
- napi_disable(&channel->napi);
- }
-
return ret;
}
@@ -881,8 +876,19 @@ static int __gsi_channel_start(struct gsi_channel *channel, bool start)
int gsi_channel_start(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
+ int ret;
- return __gsi_channel_start(channel, true);
+ /* Enable NAPI and the completion interrupt */
+ napi_enable(&channel->napi);
+ gsi_irq_ieob_enable_one(gsi, channel->evt_ring_id);
+
+ ret = __gsi_channel_start(channel, true);
+ if (ret) {
+ gsi_irq_ieob_disable_one(gsi, channel->evt_ring_id);
+ napi_disable(&channel->napi);
+ }
+
+ return ret;
}
static int gsi_channel_stop_retry(struct gsi_channel *channel)
@@ -907,16 +913,15 @@ static int gsi_channel_stop_retry(struct gsi_channel *channel)
static int __gsi_channel_stop(struct gsi_channel *channel, bool stop)
{
- struct gsi *gsi = channel->gsi;
int ret;
+ /* Wait for any underway transactions to complete before stopping. */
gsi_channel_trans_quiesce(channel);
ret = stop ? gsi_channel_stop_retry(channel) : 0;
- if (!ret) {
- gsi_irq_ieob_disable_one(gsi, channel->evt_ring_id);
- napi_disable(&channel->napi);
- }
+ /* Finally, ensure NAPI polling has finished. */
+ if (!ret)
+ napi_synchronize(&channel->napi);
return ret;
}
@@ -925,8 +930,17 @@ static int __gsi_channel_stop(struct gsi_channel *channel, bool stop)
int gsi_channel_stop(struct gsi *gsi, u32 channel_id)
{
struct gsi_channel *channel = &gsi->channel[channel_id];
+ int ret;
- return __gsi_channel_stop(channel, true);
+ /* Only disable the completion interrupt if stop is successful */
+ ret = __gsi_channel_stop(channel, true);
+ if (ret)
+ return ret;
+
+ gsi_irq_ieob_disable_one(gsi, channel->evt_ring_id);
+ napi_disable(&channel->napi);
+
+ return 0;
}
/* Reset and reconfigure a channel, (possibly) enabling the doorbell engine */
No completion interrupts will occur while an endpoint is suspended, nor when a channel has been stopped for suspend. So there's no need to disable the interrupt during suspend and re-enable it when resuming. Without any interrupts occurring, there is no need to disable/re-enable NAPI for channel suspend/resume either. We'll only enable NAPI and the interrupt when we first start the channel, and disable it again only when it's "really" stopped. To accomplish this, move the enable/disable calls out of __gsi_channel_start() and __gsi_channel_stop(), and into gsi_channel_start() and gsi_channel_stop() instead. Add a call to napi_synchronize() to gsi_channel_suspend(), to ensure NAPI polling is done before moving on. Signed-off-by: Alex Elder <elder@linaro.org> --- v2: Consolidate preparatory patch into the "real" one. v2: Update code for *both* NAPI and the completion interrupt. v2: Use common return path in gsi_channel_start(). drivers/net/ipa/gsi.c | 44 ++++++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 15 deletions(-) -- 2.27.0