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From:   Georgi Djakov <georgi.djakov@linaro.org>
To:     gregkh@linuxfoundation.org
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        georgi.djakov@linaro.org
Subject: [PATCH 1/1] interconnect: qcom: Fix uninitialized tcs_cmd::wait
Date:   Wed, 15 Apr 2020 16:03:27 +0300
Message-Id: <20200415130327.23059-2-georgi.djakov@linaro.org>
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From: Mike Tipton <mdtipton@codeaurora.org>

Currently, if tcs_cmd_gen is called with commit=false, then
tcs_cmd::wait is left uninitialized. Since the tcs_cmd structures passed
to this function aren't zero-initialized, then we're left with random
wait values. This results in waiting for completion for more commands
than is necessary, depending on what's on the stack at the time.

Removing the unnecessary if-condition fixes this, but add an explicit
memset of the tcs_cmd structure as well to ensure predictable behavior
if more tcs_cmd members are added in the future.

Fixes: 976daac4a1c5 ("interconnect: qcom: Consolidate interconnect RPMh support")
Signed-off-by: Mike Tipton <mdtipton@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200319231021.18108-1-mdtipton@codeaurora.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
 drivers/interconnect/qcom/bcm-voter.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c
index 2adfde8cdf19..2a11a63e7217 100644
--- a/drivers/interconnect/qcom/bcm-voter.c
+++ b/drivers/interconnect/qcom/bcm-voter.c
@@ -96,6 +96,8 @@ static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
 	if (!cmd)
 		return;
 
+	memset(cmd, 0, sizeof(*cmd));
+
 	if (vote_x == 0 && vote_y == 0)
 		valid = false;
 
@@ -112,8 +114,7 @@ static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
 	 * Set the wait for completion flag on command that need to be completed
 	 * before the next command.
 	 */
-	if (commit)
-		cmd->wait = true;
+	cmd->wait = commit;
 }
 
 static void tcs_list_gen(struct list_head *bcm_list, int bucket,