Re: [RFC PATCH v3 2/2] fpga: set owner of fpga_manager_ops for existing low-level modules

[Marco Pagani]

On 2023-12-18 21:33, Greg Kroah-Hartman wrote:
> On Mon, Dec 18, 2023 at 09:28:09PM +0100, Marco Pagani wrote:
>> This patch tentatively set the owner field of fpga_manager_ops to
>> THIS_MODULE for existing fpga manager low-level control modules.
>>
>> Signed-off-by: Marco Pagani <marpagan@xxxxxxxxxx>
>> ---
>>  drivers/fpga/altera-cvp.c             | 1 +
>>  drivers/fpga/altera-pr-ip-core.c      | 1 +
>>  drivers/fpga/altera-ps-spi.c          | 1 +
>>  drivers/fpga/dfl-fme-mgr.c            | 1 +
>>  drivers/fpga/ice40-spi.c              | 1 +
>>  drivers/fpga/lattice-sysconfig.c      | 1 +
>>  drivers/fpga/machxo2-spi.c            | 1 +
>>  drivers/fpga/microchip-spi.c          | 1 +
>>  drivers/fpga/socfpga-a10.c            | 1 +
>>  drivers/fpga/socfpga.c                | 1 +
>>  drivers/fpga/stratix10-soc.c          | 1 +
>>  drivers/fpga/tests/fpga-mgr-test.c    | 1 +
>>  drivers/fpga/tests/fpga-region-test.c | 1 +
>>  drivers/fpga/ts73xx-fpga.c            | 1 +
>>  drivers/fpga/versal-fpga.c            | 1 +
>>  drivers/fpga/xilinx-spi.c             | 1 +
>>  drivers/fpga/zynq-fpga.c              | 1 +
>>  drivers/fpga/zynqmp-fpga.c            | 1 +
>>  18 files changed, 18 insertions(+)
>>
>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>> index 4ffb9da537d8..aeb913547dd8 100644
>> --- a/drivers/fpga/altera-cvp.c
>> +++ b/drivers/fpga/altera-cvp.c
>> @@ -520,6 +520,7 @@ static const struct fpga_manager_ops altera_cvp_ops = {
>>  	.write_init	= altera_cvp_write_init,
>>  	.write		= altera_cvp_write,
>>  	.write_complete	= altera_cvp_write_complete,
>> +	.owner		= THIS_MODULE,
> 
> Note, this is not how to do this, force the compiler to set this for you
> automatically, otherwise everyone will always forget to do it.  Look at
> how functions like usb_register_driver() works.
> 
> Also, are you _sure_ that you need a module owner in this structure?  I
> still don't know why...
>

Do you mean moving the module owner field to the manager context and setting
it during registration with a helper macro?

Something like:

struct fpga_manager {
	...
	struct module *owner;
};

#define fpga_mgr_register(parent, ...) \
	__fpga_mgr_register(parent,..., THIS_MODULE)

struct fpga_manager *
__fpga_mgr_register(struct device *parent, ..., struct module *owner)
{
	...
	mgr->owner = owner;
}

Thanks,
Marco