From 48ca6e5fa4ffc40a14fe45bd5499428a5a108a68 Mon Sep 17 00:00:00 2001 From: Marco Pagani Date: Wed, 25 Jan 2023 15:06:22 +0100 Subject: [PATCH] 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 Acked-by: Xu Yilun Link: https://lore.kernel.org/r/20230125140622.176870-1-marpagan@redhat.com Signed-off-by: Xu Yilun --- drivers/fpga/fpga-bridge.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c index 727704431f61..5cd40acab5bf 100644 --- a/drivers/fpga/fpga-bridge.c +++ b/drivers/fpga/fpga-bridge.c @@ -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); -- 2.34.1