[PATCH v13 8/8] interconnect: Revert to previous config if any request fails

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



When consumers report their bandwidth needs with icc_set_bw(), it's
possible that the requested amount of bandwidth is not available or just
the new configuration fails to apply on some path. In this case revert to
the previous configuration and propagate the error back to the consumers
to let them know that bandwidth is not available, hardware is busy or
whatever error is returned by the interconnect platform driver.

Signed-off-by: Georgi Djakov <georgi.djakov@xxxxxxxxxx>
---
 drivers/interconnect/core.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 8091d998549a..6005a1c189f6 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -414,14 +414,18 @@ EXPORT_SYMBOL_GPL(of_icc_get);
 int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
 {
 	struct icc_node *node;
+	u32 old_avg, old_peak;
 	size_t i;
 	int ret;
 
-	if (!path)
+	if (!path || !path->num_nodes)
 		return 0;
 
 	mutex_lock(&icc_lock);
 
+	old_avg = path->reqs[0].avg_bw;
+	old_peak = path->reqs[0].peak_bw;
+
 	for (i = 0; i < path->num_nodes; i++) {
 		node = path->reqs[i].node;
 
@@ -434,10 +438,19 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
 	}
 
 	ret = apply_constraints(path);
-	if (ret)
+	if (ret) {
 		pr_debug("interconnect: error applying constraints (%d)\n",
 			 ret);
 
+		for (i = 0; i < path->num_nodes; i++) {
+			node = path->reqs[i].node;
+			path->reqs[i].avg_bw = old_avg;
+			path->reqs[i].peak_bw = old_peak;
+			aggregate_requests(node);
+		}
+		apply_constraints(path);
+	}
+
 	mutex_unlock(&icc_lock);
 
 	return ret;



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux