From: Will Deacon <will@kernel.org>
Date: Mon, 4 Nov 2019 15:58:15 +0000
Subject: firmware: qcom: scm: Ensure 'a0' status code is treated as signed
Git-commit: ff34f3cce278a0982a7b66b1afaed6295141b1fc
Patch-mainline: 5.5-rc1
References: bnc#1151927 5.3.17

The 'a0' member of 'struct arm_smccc_res' is declared as 'unsigned long',
however the Qualcomm SCM firmware interface driver expects to receive
negative error codes via this field, so ensure that it's cast to 'long'
before comparing to see if it is less than 0.

Cc: <stable@vger.kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/firmware/qcom_scm-64.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -150,7 +150,7 @@ static int qcom_scm_call(struct device *
 		kfree(args_virt);
 	}
 
-	if (res->a0 < 0)
+	if ((long)res->a0 < 0)
 		return qcom_scm_remap_error(res->a0);
 
 	return 0;