hi Danilo, You'd have to use copy_to_user! Rgds J Kang
From: Danilo Reinhardt <Danilo.Reinhardt@xxxxxxxxxxxx> To: Kernel Newbies <kernelnewbies@xxxxxxxxxxxx> Subject: _IOWR ioctl Date: Tue, 27 Jul 2004 11:32:08 +0200
Hi,
i want to use an read and write ioctl. My problem is that i dont know what i have to do to write something back from kernel to the userland app that has called ioctl()?
To exchange data i've a struct with one parameter used as input for the kernel and another as output to the userspace.
struct st_cmd_getBridgeInfo { __u32 bridge; // param for kernel char info[4092]; // result to userspace };
#define TIS_IOC_GETBRIDGEINFO _IOWR(0x88, 1, struct st_cmd_getBridgeInfo)
I guessed that i have to do it this way, but if i write something to the info array in kernel ive got nothing at userspace. The input to kernel works very well. Do i have to use copy_to_user or something?
Any suggestions?
Bye Dan
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