[PATCH RFC 4/7] i3c: master: Reject IBI requests from non-IBI-capable devices

[Adrian Hunter]

i3c_device_request_ibi() does not verify that a device advertises IBI
support before attempting to set up IBI handling.

Add a check for I3C_BCR_IBI_REQ_CAP and fail with -EOPNOTSUPP when IBI
support is not reported by the device.  This keeps IBI setup consistent
with other IBI-related functionality, such as exposing wakeup capability
only for IBI-capable devices.

Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
---
 drivers/i3c/device.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c
index 101eaa77de68..307ca6dc04ca 100644
--- a/drivers/i3c/device.c
+++ b/drivers/i3c/device.c
@@ -205,12 +205,14 @@ int i3c_device_request_ibi(struct i3c_device *dev,
 		return ret;
 
 	i3c_bus_normaluse_lock(dev->bus);
-	if (dev->desc) {
+	if (!dev->desc) {
+		ret = -ENOENT;
+	} else if (!(dev->desc->info.bcr & I3C_BCR_IBI_REQ_CAP)) {
+		ret = -EOPNOTSUPP;
+	} else {
 		mutex_lock(&dev->desc->ibi_lock);
 		ret = i3c_dev_request_ibi_locked(dev->desc, req);
 		mutex_unlock(&dev->desc->ibi_lock);
-	} else {
-		ret = -ENOENT;
 	}
 	i3c_bus_normaluse_unlock(dev->bus);
 
-- 
2.53.0