[libcamera-devel] [PATCH 05/11] libcamera: v4l2_controls: Fix usage of strerror()

[Jacopo Mondi]

On failure, the return code from V4L2Device::ioctl() is the negative error
code set by the failed ::ioctl() system call. When the return code of
V4L2Device::ioctl() is provided to strerror() it has to be negated again
to obtain the positive error code. Fix a few wrong usages of the return
code which provided to the strerror() function a negative error code.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/libcamera/v4l2_device.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 98639bd0f07f..179476e9afad 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -201,13 +201,13 @@ int V4L2Device::getControls(ControlList *ctrls)
 		/* Generic validation error. */
 		if (errorIdx == 0 || errorIdx >= count) {
 			LOG(V4L2, Error) << "Unable to read controls: "
-					 << strerror(ret);
+					 << strerror(-ret);
 			return -EINVAL;
 		}
 
 		/* A specific control failed. */
 		LOG(V4L2, Error) << "Unable to read control " << errorIdx
-				 << ": " << strerror(ret);
+				 << ": " << strerror(-ret);
 		count = errorIdx - 1;
 		ret = errorIdx;
 	}
@@ -291,13 +291,13 @@ int V4L2Device::setControls(ControlList *ctrls)
 		/* Generic validation error. */
 		if (errorIdx == 0 || errorIdx >= count) {
 			LOG(V4L2, Error) << "Unable to set controls: "
-					 << strerror(ret);
+					 << strerror(-ret);
 			return -EINVAL;
 		}
 
 		/* A specific control failed. */
 		LOG(V4L2, Error) << "Unable to set control " << errorIdx
-				 << ": " << strerror(ret);
+				 << ": " << strerror(-ret);
 		count = errorIdx - 1;
 		ret = errorIdx;
 	}
-- 
2.25.0