[PATCH 13/18] rpmsg: glink: Add rx done command
From: Sricharan R <hidden>
Date: 2017-08-22 14:16:08
Also in:
linux-arm-msm, linux-remoteproc, lkml
Hi,
quoted
+??? /* Take it off the tree of receive intents */ +??? if (!intent->reuse) { +??????? spin_lock(&channel->intent_lock); +??????? idr_remove(&channel->liids, intent->id); +??????? spin_unlock(&channel->intent_lock); +??? } + +??? /* Schedule the sending of a rx_done indication */ +??? spin_lock(&channel->intent_lock); +??? list_add_tail(&intent->node, &channel->done_intents); +??? spin_unlock(&channel->intent_lock); + +??? schedule_work(&channel->intent_work);Adding one more parallel path will hit performance, if this worker could not get CPU cycles or blocked by other RT or HIGH_PRIO worker on global worker pool.
The idea is, by design to have parallel non-blocking paths for rx and tx (that is done as a part of rx by sending the rx_done command), otherwise trying to send the rx_done command in the rx isr context is a problem since the tx can wait for the FIFO space and in worst case, can even lead to a potential deadlock if both the local and remote try the same. Having said that, instead of queuing this work in to the global queue, this can be put in to a local glink edge owned queue (or) a threaded isr ?, downstream does the rx_done in a client specific worker. Regards, Sricharan -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus