Thank you, guys, Now, I could understand of it and learned it.
Best Regards, Daniel (Youngwhan) Song On Thu, Jan 14, 2010 at 6:57 PM, snoppy1314 <[email protected]> wrote: > Dear Daniel： > > I think the most important reason is: the file your said is in the > user-space, while the driver code is running in the kernel-space.For the > security reason, the direct acess between these two space is forbidden. > The solution to your problem: > 1. use the /proc or /sys filesystem > 2. printk > 3. write a user-space program to read these data from driver and then save > them to a file > > > 2010-01-15 > ------------------------------ > snoppy1314 > ------------------------------ > *发件人：* Daniel (Youngwhan) Song > *发送时间：* 2010-01-15 09:53:44 > *收件人：* kernelnewbies > *抄送：* > *主题：* Why the linux does not allow the access to a file in the > devicedriver? > Hi, > > Could somebody help me to understand the reason why the linux kernel does > not allow the access to a file in the device driver? For example, for > debugging purpose, if a device driver want to log some data in a file by > using open/write/read method like in user application, how a driver can > access to a file in a specific filesystem? Any comment or docs or web pages > would be appreciated. > > Thank you, > > Dan. >
