Hi Sergei,
I understand that the commit log needs to be corrected.
(Shimoda-san's point is also correct)
If there is anything else that needs to be corrected, please point it out.
> That seems a common pattern, inlluding the Renesas sh_eth
> driver...
Yes.
If I can get an R-Car Gen2 board, I will also fix sh_eth driver.
> No, the driver's remove() method calls ravb_mdio_release() and
> that one calls
> free_mdio_bitbang() that calls module_put(); the actual reason lies
> somewehre deeper than this...
No.
Running rmmod calls delete_module() in kernel/module.c before ravb_mdio_release() is called.
delete_module()
-> try_stop_module()
-> try_release_module_ref()
In try_release_module_ref(), check refcnt and if it is counted up, ravb_mdio_release() is not
called and rmmod is terminated.
Thanks & Best Regards,
Yuusuke Ashizuka <ashiduka@xxxxxxxxxxx>
> -----Original Message-----
> From: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxx>
> Sent: Friday, July 31, 2020 1:04 AM
> To: Ashizuka, Yuusuke/芦塚 雄介 <ashiduka@xxxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2] ravb: Fixed the problem that rmmod can not
> be done
>
> Hello!
>
> On 7/30/20 1:01 PM, Yuusuke Ashizuka wrote:
>
> > ravb is a module driver, but I cannot rmmod it after insmod it.
>
> Modular. And "insmod'ing it".
>
> > ravb does mdio_init() at the time of probe, and module->refcnt
> is incremented
> > by alloc_mdio_bitbang() called after that.
>
> That seems a common pattern, inlluding the Renesas sh_eth
> driver...
>
> > Therefore, even if ifup is not performed, the driver is in use
> and rmmod cannot
> > be performed.
>
> No, the driver's remove() method calls ravb_mdio_release() and
> that one calls
> free_mdio_bitbang() that calls module_put(); the actual reason lies
> somewehre deeper
> than this... Unfortunately I don't have the affected hardware
> anymore... :-(
>
> [...]
>
> MBR, Sergei
