Re: [PATCH] Documentation/firmware_class/firmware_sample_driver.c

Anders Blomdell
2007-06-28T08:47:19Z

Marcel Holtmann wrote:
> Hi Anders,
>
>> Signed-off-by: Anders Blomdell <anders.blomdell@control.lth.se>
>>
>> Minor modifications to make the example load and unload without Oops
>>
>> This is what unpatched version generates with 2.6.21.3
>>
>> kernel: Oops: 0000 [#2]
>> ...
>> kernel: Call Trace:
>> kernel: [<c04ae541>] sysfs_create_dir+0x49/0x63
>> kernel: [<c04e76ae>] kobject_shadow_add+0xd5/0x17d
>> kernel: [<c04e7908>] kobject_set_name+0x2b/0x92
>> kernel: [<c0556444>] device_add+0x9a/0x58e
>> kernel: [<c0620b65>] klist_init+0x23/0x2e
>> kernel: [<c055bfee>] _request_firmware+0x116/0x29f
>> kernel: [<c062149f>] wait_for_completion+0x8b/0x93
>> kernel: [<c055c20b>] request_firmware+0xf/0x11
>> kernel: [<e09420d9>] sample_init+0x59/0xc0 [firmware_sample_driver]
>> kernel: [<c0446c92>] sys_init_module+0x16b7/0x17ee
>> kernel: [<c04294de>] printk+0x0/0x1f
>> kernel: [<c0488436>] mntput_no_expire+0x11/0x6e
>> kernel: [<c0404fa8>] syscall_call+0x7/0xb
>>
>>
>>
>> diff -u Documentation/firmware_class/firmware_sample_driver.c
>> /tmp/fw/firmware_sample_driver.c
>> --- Documentation/firmware_class/firmware_sample_driver.c 2007-05-24
>> 23:22:47.000000000 +0200
>> +++ /tmp/fw/firmware_sample_driver.c 2007-06-27 16:51:16.000000000 +0200
>> @@ -15,11 +15,16 @@
>>
>> #include "linux/firmware.h"
>>
>> +static void ghost_release(struct device *dev)
>> +{
>> + printk(KERN_DEBUG "firmware_sample_driver: ghost_release\n");
>> +}
>> +
>
> I know it is a sample driver, but you can't do that. You have to
> allocate the device and then free it here.
Are you sure about this? The code in the example looks very similar to the code
in "Linux Device Drivers" 3rd edition, p 382.

Regards

Anders Blomdell