Unverified Commit 48ca6e5f authored Jan 25, 2023 by Marco Pagani Committed by Xu Yilun Jan 28, 2023

fpga: bridge: return errors in the show() method of the "state" attribute



This patch changes the show() method of the "state" sysfs attribute to
propagate errors returned by the enable_show() op. In this way,
userspace can distinguish between when the bridge is actually "enabled"
(i.e., allowing signals) or "disabled" (i.e., gating signals), or when
there is an error.

Currently, enable_show() returns an integer representing the bridge's
state (enabled or disabled) or an error code. However, this integer
value is interpreted in state_show() as a bool, resulting in the method
printing "enabled" (i.e., the bridge allows signals to pass), without
propagating the error, even when enable_show() returns an error code.

Signed-off-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230125140622.176870-1-marpagan@redhat.com


Signed-off-by: Xu Yilun <yilun.xu@intel.com>

parent a73c125b

drivers/fpga/fpga-bridge.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -293,12 +293,15 @@ static ssize_t state_show(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct fpga_bridge *bridge = to_fpga_bridge(dev);
		int enable = 1;
		int state = 1;

		if (bridge->br_ops && bridge->br_ops->enable_show)
		enable = bridge->br_ops->enable_show(bridge);
		if (bridge->br_ops && bridge->br_ops->enable_show) {
		state = bridge->br_ops->enable_show(bridge);
		if (state < 0)
		return state;
		}

		return sprintf(buf, "%s\n", enable ? "enabled" : "disabled");
		return sysfs_emit(buf, "%s\n", state ? "enabled" : "disabled");
		}

		static DEVICE_ATTR_RO(name);