character driver common errors and warnings

Common Errors which most of us will face while doing character drivers

1) Multiple definitions of the variable {bcoz of wrong use of extern}

2)control reaches end of non-void function{bcoz not returning any value to that non-void function}

3)warning: variable ‘lscullqset’ set but not used {bcoz variables initilised but not used}
4)***-1 Unknown symbol in module {bcoz u have used a variable which was not able to reference the driver properly}
5)warning: assignment from incompatible pointer type [enabled by default]
/home/project_05/devwrite.c:6:20: warning: variable ‘lscullqset’ set but not used [-Wunused-but-set-variable]
/home/project_05/devwrite.c:4:49: warning: unused variable ‘device_size’ [-Wunused-variable]
/home/project_05/devwrite.c:4:35: warning: unused variable ‘data_size’ [-Wunused-variable]
/home/project_05/devwrite.c:4:22: warning: unused variable ‘qset_size’ [-Wunused-variable]
/home/project_05/devwrite.c:4:7: warning: unused variable ‘quantum_size’ [-Wunuse