From b8b730357967ac2ec49dcffd2dc2b354f0fdd011 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Thu, 7 May 2015 15:53:58 +0300 Subject: [PATCH] mei: consume flow control on the first chunk of writing Consume the write flow control on the first chunk of the write instead of on the buffer completion. We can safely assume that the consequent chunks have the flow control granted. This addresses two issues: 1. Blocks other callbacks from the same client riding on the client's flow control and prevents interleaving of messages as FW cannot distinguish between two messages from the same client. 2. Fixes single buffer flow control arbitration in a clean way, without connection/disconnection book keeping Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/client.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c index 36706705dfdc..ce88c2199b2c 100644 --- a/drivers/misc/mei/client.c +++ b/drivers/misc/mei/client.c @@ -755,9 +755,6 @@ void mei_cl_set_disconnected(struct mei_cl *cl) if (!WARN_ON(cl->me_cl->connect_count == 0)) cl->me_cl->connect_count--; - if (cl->me_cl->connect_count == 0) - cl->me_cl->mei_flow_ctrl_creds = 0; - mei_me_cl_put(cl->me_cl); cl->me_cl = NULL; } @@ -1272,6 +1269,7 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb, u32 msg_slots; int slots; int rets; + bool first_chunk; if (WARN_ON(!cl || !cl->dev)) return -ENODEV; @@ -1280,7 +1278,9 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb, buf = &cb->buf; - rets = mei_cl_flow_ctrl_creds(cl); + first_chunk = cb->buf_idx == 0; + + rets = first_chunk ? mei_cl_flow_ctrl_creds(cl) : 1; if (rets < 0) return rets; @@ -1327,12 +1327,14 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb, cb->buf_idx += mei_hdr.length; cb->completed = mei_hdr.msg_complete == 1; - if (mei_hdr.msg_complete) { + if (first_chunk) { if (mei_cl_flow_ctrl_reduce(cl)) return -EIO; - list_move_tail(&cb->list, &dev->write_waiting_list.list); } + if (mei_hdr.msg_complete) + list_move_tail(&cb->list, &dev->write_waiting_list.list); + return 0; } @@ -1411,21 +1413,19 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking) if (rets) goto err; + rets = mei_cl_flow_ctrl_reduce(cl); + if (rets) + goto err; + cl->writing_state = MEI_WRITING; cb->buf_idx = mei_hdr.length; cb->completed = mei_hdr.msg_complete == 1; out: - if (mei_hdr.msg_complete) { - rets = mei_cl_flow_ctrl_reduce(cl); - if (rets < 0) - goto err; - + if (mei_hdr.msg_complete) list_add_tail(&cb->list, &dev->write_waiting_list.list); - } else { + else list_add_tail(&cb->list, &dev->write_list.list); - } - if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) { -- 2.45.2