releases/5.7.16/firmware-qcom_scm-fix-legacy-convention-scm-accessors.patch

From b88c28280c3f7097546db93824686db1e7dceee1 Mon Sep 17 00:00:00 2001
From: Jonathan McDowell <noodles@earth.li>
Date: Sat, 4 Jul 2020 18:23:34 +0100
Subject: firmware: qcom_scm: Fix legacy convention SCM accessors

From: Jonathan McDowell <noodles@earth.li>

commit b88c28280c3f7097546db93824686db1e7dceee1 upstream.

The move to a combined driver for the QCOM SCM hardware changed the
io_writel and io_readl helpers to use non-atomic calls, despite the
commit message saying that atomic was a better option. This breaks these
helpers on hardware that uses the old legacy convention (access fails
with a -95 return code). Switch back to using the atomic calls.

Observed as a failure routing GPIO interrupts to the Apps processor on
an IPQ8064; fix is confirmed as correctly allowing the interrupts to be
routed and observed.

Reviewed-by: Elliot Berman <eberman@codeaurora.org>
Fixes: 57d3b816718c ("firmware: qcom_scm: Remove thin wrappers")
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Link: https://lore.kernel.org/r/20200704172334.GA759@earth.li
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/firmware/qcom_scm.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -391,7 +391,7 @@ static int __qcom_scm_set_dload_mode(str
 
 	desc.args[1] = enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
 
-	return qcom_scm_call(__scm->dev, &desc, NULL);
+	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
 }
 
 static void qcom_scm_set_download_mode(bool enable)
@@ -650,7 +650,7 @@ int qcom_scm_io_readl(phys_addr_t addr,
 	int ret;
 
 
-	ret = qcom_scm_call(__scm->dev, &desc, &res);
+	ret = qcom_scm_call_atomic(__scm->dev, &desc, &res);
 	if (ret >= 0)
 		*val = res.result[0];
 
@@ -669,8 +669,7 @@ int qcom_scm_io_writel(phys_addr_t addr,
 		.owner = ARM_SMCCC_OWNER_SIP,
 	};
 
-
-	return qcom_scm_call(__scm->dev, &desc, NULL);
+	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
 }
 EXPORT_SYMBOL(qcom_scm_io_writel);