[PATCH] firmware: qcom_scm: Fix legacy convention SCM accessors

From: Jonathan McDowell
Date: Sat Jul 04 2020 - 13:23:57 EST


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.

Fixes: 57d3b816718c ("firmware: qcom_scm: Remove thin wrappers")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jonathan McDowell <noodles@xxxxxxxx>
---
drivers/firmware/qcom_scm.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 0e7233a20f34..d4fda210adfe 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -391,7 +391,7 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)

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, unsigned int *val)
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, unsigned int val)
.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);

--
2.20.1