soc: qcom: rpmh-rsc: Avoid unnecessary checks on irq-done response

The RSC interrupt is issued only after the request is complete. For
fire-n-forget requests, the irq-done interrupt is sent after issuing the
RPMH request and for response-required request, the interrupt is
triggered only after all the requests are complete.

These unnecessary checks in the interrupt handler issues AHB reads from
a critical path. Lets remove them and clean up error handling in
rpmh_request data structures.

Co-developed-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221116112246.2640648-2-abel.vesa@linaro.org

drivers/soc/qcom/rpmh-internal.h

@@ -59,7 +59,6 @@ struct tcs_group {
  * @cmd: the payload that will be part of the @msg
  * @completion: triggered when request is done
  * @dev: the device making the request
- * @err: err return from the controller
  * @needs_free: check to free dynamically allocated request object
  */
 struct rpmh_request {
@@ -67,7 +66,6 @@ struct rpmh_request {
 	struct tcs_cmd cmd[MAX_RPMH_PAYLOAD];
 	struct completion *completion;
 	const struct device *dev;
-	int err;
 	bool needs_free;
 };
 
@@ -144,7 +142,7 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
 void rpmh_rsc_invalidate(struct rsc_drv *drv);
 void rpmh_rsc_write_next_wakeup(struct rsc_drv *drv);
 
-void rpmh_tx_done(const struct tcs_request *msg, int r);
+void rpmh_tx_done(const struct tcs_request *msg);
 int rpmh_flush(struct rpmh_ctrlr *ctrlr);
 
 #endif /* __RPM_INTERNAL_H__ */

drivers/soc/qcom/rpmh-rsc.c

@@ -439,10 +439,9 @@ static void enable_tcs_irq(struct rsc_drv *drv, int tcs_id, bool enable)
 static irqreturn_t tcs_tx_done(int irq, void *p)
 {
 	struct rsc_drv *drv = p;
-	int i, j, err = 0;
+	int i;
 	unsigned long irq_status;
 	const struct tcs_request *req;
-	struct tcs_cmd *cmd;
 
 	irq_status = readl_relaxed(drv->tcs_base + drv->regs[RSC_DRV_IRQ_STATUS]);
 
@@ -451,22 +450,7 @@ static irqreturn_t tcs_tx_done(int irq, void *p)
 		if (WARN_ON(!req))
 			goto skip;
 
-		err = 0;
-		for (j = 0; j < req->num_cmds; j++) {
-			u32 sts;
-
-			cmd = &req->cmds[j];
-			sts = read_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_STATUS], i, j);
-			if (!(sts & CMD_STATUS_ISSUED) ||
-			   ((req->wait_for_compl || cmd->wait) &&
-			   !(sts & CMD_STATUS_COMPL))) {
-				pr_err("Incomplete request: %s: addr=%#x data=%#x",
-				       drv->name, cmd->addr, cmd->data);
-				err = -EIO;
-			}
-		}
-
-		trace_rpmh_tx_done(drv, i, req, err);
+		trace_rpmh_tx_done(drv, i, req);
 
 		/*
 		 * If wake tcs was re-purposed for sending active
@@ -491,7 +475,7 @@ skip:
 		spin_unlock(&drv->lock);
 		wake_up(&drv->tcs_wait);
 		if (req)
-			rpmh_tx_done(req, err);
+			rpmh_tx_done(req);
 	}
 
 	return IRQ_HANDLED;

drivers/soc/qcom/rpmh.c

@@ -76,19 +76,13 @@ static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev)
 	return &drv->client;
 }
 
-void rpmh_tx_done(const struct tcs_request *msg, int r)
+void rpmh_tx_done(const struct tcs_request *msg)
 {
 	struct rpmh_request *rpm_msg = container_of(msg, struct rpmh_request,
 						    msg);
 	struct completion *compl = rpm_msg->completion;
 	bool free = rpm_msg->needs_free;
 
-	rpm_msg->err = r;
-
-	if (r)
-		dev_err(rpm_msg->dev, "RPMH TX fail in msg addr=%#x, err=%d\n",
-			rpm_msg->msg.cmds[0].addr, r);
-
 	if (!compl)
 		goto exit;
 
@@ -194,7 +188,7 @@ static int __rpmh_write(const struct device *dev, enum rpmh_state state,
 	} else {
 		/* Clean up our call by spoofing tx_done */
 		ret = 0;
-		rpmh_tx_done(&rpm_msg->msg, ret);
+		rpmh_tx_done(&rpm_msg->msg);
 	}
 
 	return ret;

drivers/soc/qcom/trace-rpmh.h

@@ -14,16 +14,15 @@
 
 TRACE_EVENT(rpmh_tx_done,
 
-	TP_PROTO(struct rsc_drv *d, int m, const struct tcs_request *r, int e),
+	TP_PROTO(struct rsc_drv *d, int m, const struct tcs_request *r),
 
-	TP_ARGS(d, m, r, e),
+	TP_ARGS(d, m, r),
 
 	TP_STRUCT__entry(
 			 __string(name, d->name)
 			 __field(int, m)
 			 __field(u32, addr)
 			 __field(u32, data)
-			 __field(int, err)
 	),
 
 	TP_fast_assign(
@@ -31,12 +30,10 @@ TRACE_EVENT(rpmh_tx_done,
 		       __entry->m = m;
 		       __entry->addr = r->cmds[0].addr;
 		       __entry->data = r->cmds[0].data;
-		       __entry->err = e;
 	),
 
-	TP_printk("%s: ack: tcs-m: %d addr: %#x data: %#x errno: %d",
-		  __get_str(name), __entry->m, __entry->addr, __entry->data,
-		  __entry->err)
+	TP_printk("%s: ack: tcs-m: %d addr: %#x data: %#x",
+		  __get_str(name), __entry->m, __entry->addr, __entry->data)
 );
 
 TRACE_EVENT(rpmh_send_msg,