qseecom:Fix race condition while voting for clocks
In the current functionality, if DFAB clock is already on and a
request is made to turn on SFPB clock, the DFAB clock is turned
off and SFPB clock is turned on and vice-versa.
The above situation can lead to unexpected errors. The current fix
makes sure that clocks that are on are not voted to be off without
explicit request.
Change-Id: I6c3230e23b105c049cdb0aace579b8a176328c84
Signed-off-by: Ramesh Masavarapu <rameshm@codeaurora.org>
(cherry picked from commit 8d7565828aca6023ca968d2e5350737bd6d86215)
diff --git a/drivers/misc/qseecom.c b/drivers/misc/qseecom.c
index b8f51495..179eec71 100644
--- a/drivers/misc/qseecom.c
+++ b/drivers/misc/qseecom.c
@@ -142,7 +142,6 @@
static DEFINE_MUTEX(pil_access_lock);
static DEFINE_MUTEX(qsee_bw_mutex);
-static DEFINE_MUTEX(qsee_sfpb_bw_mutex);
static DEFINE_MUTEX(app_access_lock);
static int qsee_bw_count;
@@ -1196,28 +1195,41 @@
case CLK_DFAB:
mutex_lock(&qsee_bw_mutex);
if (!qsee_bw_count) {
- ret = msm_bus_scale_client_update_request(
- qsee_perf_client, 1);
+ if (qsee_sfpb_bw_count > 0)
+ ret = msm_bus_scale_client_update_request(
+ qsee_perf_client, 3);
+ else
+ ret = msm_bus_scale_client_update_request(
+ qsee_perf_client, 1);
if (ret)
pr_err("DFAB Bandwidth req failed (%d)\n",
ret);
else
qsee_bw_count++;
+ } else {
+ qsee_bw_count++;
}
mutex_unlock(&qsee_bw_mutex);
break;
case CLK_SFPB:
- mutex_lock(&qsee_sfpb_bw_mutex);
+ mutex_lock(&qsee_bw_mutex);
if (!qsee_sfpb_bw_count) {
- ret = msm_bus_scale_client_update_request(
- qsee_perf_client, 2);
+ if (qsee_bw_count > 0)
+ ret = msm_bus_scale_client_update_request(
+ qsee_perf_client, 3);
+ else
+ ret = msm_bus_scale_client_update_request(
+ qsee_perf_client, 2);
+
if (ret)
pr_err("SFPB Bandwidth req failed (%d)\n",
ret);
else
qsee_sfpb_bw_count++;
+ } else {
+ qsee_sfpb_bw_count++;
}
- mutex_unlock(&qsee_sfpb_bw_mutex);
+ mutex_unlock(&qsee_bw_mutex);
break;
default:
pr_err("Clock type not defined\n");
@@ -1236,29 +1248,44 @@
switch (clk_type) {
case CLK_DFAB:
mutex_lock(&qsee_bw_mutex);
- if (qsee_bw_count > 0) {
- if (qsee_bw_count-- == 1) {
+ if (qsee_bw_count == 0) {
+ pr_err("Client error.Extra call to disable DFAB clk\n");
+ mutex_unlock(&qsee_bw_mutex);
+ return;
+ }
+
+ if ((qsee_bw_count > 0) && (qsee_bw_count-- == 1)) {
+ if (qsee_sfpb_bw_count > 0)
+ ret = msm_bus_scale_client_update_request(
+ qsee_perf_client, 2);
+ else
ret = msm_bus_scale_client_update_request(
qsee_perf_client, 0);
- if (ret)
- pr_err("SFPB Bandwidth req fail (%d)\n",
+ if (ret)
+ pr_err("SFPB Bandwidth req fail (%d)\n",
ret);
- }
}
mutex_unlock(&qsee_bw_mutex);
break;
case CLK_SFPB:
- mutex_lock(&qsee_sfpb_bw_mutex);
- if (qsee_sfpb_bw_count > 0) {
- if (qsee_sfpb_bw_count-- == 1) {
+ mutex_lock(&qsee_bw_mutex);
+ if (qsee_sfpb_bw_count == 0) {
+ pr_err("Client error.Extra call to disable SFPB clk\n");
+ mutex_unlock(&qsee_bw_mutex);
+ return;
+ }
+ if ((qsee_sfpb_bw_count > 0) && (qsee_sfpb_bw_count-- == 1)) {
+ if (qsee_bw_count > 0)
+ ret = msm_bus_scale_client_update_request(
+ qsee_perf_client, 1);
+ else
ret = msm_bus_scale_client_update_request(
qsee_perf_client, 0);
- if (ret)
- pr_err("SFPB Bandwidth req fail (%d)\n",
+ if (ret)
+ pr_err("SFPB Bandwidth req fail (%d)\n",
ret);
- }
}
- mutex_unlock(&qsee_sfpb_bw_mutex);
+ mutex_unlock(&qsee_bw_mutex);
break;
default:
pr_err("Clock type not defined\n");