Messages in this thread | | | Date | Mon, 13 Mar 2023 12:47:17 +0200 | Subject | Re: [PATCH v2] USB: serial: xr: Add TIOCGRS485 and TIOCSRS485 ioctls | From | Jarkko Sonninen <> |
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Hello,
It uses only one flag from the struct from user. Would it be better to store only that to state ?
Do I need locking at all in that case ?
The whole struct is stored just in case, if someone would implement other functionality later.
- Jarkko
Oliver Neukum kirjoitti 13/03/2023 klo 11.54: > > > On 13.03.23 09:27, Jarkko Sonninen wrote: >> Add support for RS-485 in Exar USB adapters. >> RS-485 mode is controlled by TIOCGRS485 and TIOCSRS485 ioctls. >> Gpio mode register is set to enable RS-485. >> >> Signed-off-by: Jarkko Sonninen <kasper@iki.fi> > > > Hi, > > I am sorry, but locking is really broken here. All these contexts can > sleep. > There is no need for a spinlock. As far as you need locking, just use > a mutex. > > Secondly, if xr_set_rs485_config() needs locking, so will > xr_get_rs485_config() > or you can get the case that you return half a new and half an old > state to user > space. > > Regards > Oliver
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