gpu: nvgpu: vgpu: ring doorbell after enabling TSG

In some use cases client will disable and preempt TSG and then re-enable it
using IOCTLs provided

In case there is only one context getting re-enabled and there is no other job
submission in parallel runlist fetcher will just sleep until doorbell is
received next time

This causes above mentioned test cases to stall after re-enabling TSG
until some one submits a new job and triggers a doorbell

Fix this by explicitly triggering doorbell in vgpu code
after we enable all channels in TSG.

Bug 2205192

Change-Id: I25d643e06152adc6aaf874baf610316f6cd8f13f
Signed-off-by: Aparna Das <aparnad@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1772948
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/gv11b/vgpu_tsg_gv11b.c b/drivers/gpu/nvgpu/vgpu/gv11b/vgpu_tsg_gv11b.c
index 367c1299..e42bea1f 100644
--- a/drivers/gpu/nvgpu/vgpu/gv11b/vgpu_tsg_gv11b.c
+++ b/drivers/gpu/nvgpu/vgpu/gv11b/vgpu_tsg_gv11b.c
@@ -58,3 +58,23 @@ int vgpu_gv11b_tsg_bind_channel(struct tsg_gk20a *tsg,
 
         return err;
 }
+
+int vgpu_gv11b_enable_tsg(struct tsg_gk20a *tsg)
+{
+        struct gk20a *g = tsg->g;
+        struct channel_gk20a *ch;
+        struct channel_gk20a *last_ch = NULL;
+
+        nvgpu_rwsem_down_read(&tsg->ch_list_lock);
+        nvgpu_list_for_each_entry(ch, &tsg->ch_list, channel_gk20a, ch_entry) {
+                g->ops.fifo.enable_channel(ch);
+                last_ch = ch;
+        }
+        nvgpu_rwsem_up_read(&tsg->ch_list_lock);
+
+        if (last_ch)
+                g->ops.fifo.ring_channel_doorbell(last_ch);
+
+        return 0;
+}
+