[PATCH 2/2] firmware: qcom: scm: Fix interrupted SCM calls

From: Andy Gross
Date: Sat Aug 20 2016 - 01:51:54 EST


This patch fixes an issue with the SCM64 calls. Sometimes SCM calls can
be interrupted and return early. When this happens, the contents of
register 6 will contain a session ID that is required when resuming the
SCM call.

Signed-off-by: Andy Gross <andy.gross@xxxxxxxxxx>
---
drivers/firmware/qcom_scm-64.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index 4a0f5ea..1851294 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -131,10 +131,12 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
qcom_smccc_convention,
ARM_SMCCC_OWNER_SIP, fn_id);

+ res->a6 = 0;
+
do {
arm_smccc_smc(cmd, desc->arginfo, desc->args[0],
- desc->args[1], desc->args[2], x5, 0, 0,
- res);
+ desc->args[1], desc->args[2], x5, res->a6,
+ 0, res);
} while (res->a0 == QCOM_SCM_INTERRUPTED);

mutex_unlock(&qcom_scm_lock);
--
1.9.1