OK. I'll make my patch based on Mark's patch. Thanks. Daeseok Youn. 2014-04-27 3:48 GMT+09:00 Dan Carpenter <dan.carpenter@xxxxxxxxxx>: > On Sat, Apr 26, 2014 at 11:39:38AM +0900, DaeSeok Youn wrote: >> Hi, >> >> please check below my comments. >> >> 2014-04-25 23:41 GMT+09:00 Mark Hounschell <markh@xxxxxxxxxx>: >> > On 04/25/2014 08:59 AM, Dan Carpenter wrote: >> >> On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: >> >>> On 04/25/2014 07:02 AM, DaeSeok Youn wrote: >> >>>> Hi, Dan. >> >>>> >> >>>> 2014-04-25 18:26 GMT+09:00 Dan Carpenter <dan.carpenter@xxxxxxxxxx>: >> >>>>> Mark, maybe you should add yourself to the MAINTAINERS entry for this >> >>>>> driver? >> >>>>> >> >>> >> >>> I'll look into this. I am clueless on what that would actually mean. >> >>> >> >> >> >> Just add your name with Lidza in the MAINTAINERS file so that people >> >> will CC you on all the patches. >> >> >> >> DIGI EPCA PCI PRODUCTS >> >> M: Lidza Louina <lidza.louina@xxxxxxxxx> >> >> L: driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx >> >> S: Maintained >> >> F: drivers/staging/dgap/ >> >> >> >> You don't have to do it if you don't want to, but you seem to be working >> >> on this driver and I'm going to refer questions to you either way. :P >> >> >> >>>>> On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: >> >>>>>> @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) >> >>>>>> /* Register tty devices */ >> >>>>>> rc = tty_register_driver(brd->SerialDriver); >> >>>>>> if (rc < 0) >> >>>>>> - return rc; >> >>>>>> + goto free_print_ttys; >> >>>>>> + >> >>>>>> brd->dgap_Major_Serial_Registered = TRUE; >> >>>>>> dgap_BoardsByMajor[brd->SerialDriver->major] = brd; >> >>>>>> brd->dgap_Serial_Major = brd->SerialDriver->major; >> >>>>>> @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) >> >>>>>> /* Register Transparent Print devices */ >> >>>>>> rc = tty_register_driver(brd->PrintDriver); >> >>>>>> if (rc < 0) >> >>>>>> - return rc; >> >>>>>> + goto unregister_serial_drv; >> >>>>>> + >> >>>>>> brd->dgap_Major_TransparentPrint_Registered = TRUE; >> >>>>>> dgap_BoardsByMajor[brd->PrintDriver->major] = brd; >> >>>>>> brd->dgap_TransparentPrint_Major = brd->PrintDriver->major; >> >>>>>> } >> >>>>>> >> >>>>>> return rc; >> >>>>>> + >> >>>>>> +unregister_serial_drv: >> >>>>>> + tty_unregister_driver(brd->SerialDriver); >> >>>>> >> >>>>> We only register the ->SerialDriver if someone else hasn't registered it >> >>>>> first? So this should be: >> >>>>> >> >>>>> if (we_were_the_ones_who_registered_the_serial_driver) >> >>>>> tty_unregister_driver(brd->SerialDriver); >> >>>>> >> >>>>> I haven't followed looked at this. Who else is registering the serial >> >>>>> driver? You have looked at this, what do you think? Or Mark. >> >>>> >> >>> >> >>> registering the brd->XxxxxDriver is only done when a board is detected >> >>> and only during the firmware_load process. If we fail to >> >>> tty_register_driver do we _need_ to tty_unregister_driver? Isn't that >> >>> like freeing after an alloc failure? >> >> >> >> The allocation is conditional so the free should be conditional. If we >> >> didn't allocate it, then we shouldn't free it. >> >> >> >> It wouldn't have even been a question except I'm not sure the allocation >> >> is *really* conditional because brd->dgap_Major_Serial_Registered might >> >> always be "false" like you guys seem to be saying. >> >> >> >>> >> >>>> I think brd struct is from dgap_Board array as global static variable >> >>>> when this function is >> >>>> called. So brd->dgap_Major_Serial_Registered is always "false". >> >>>> If dgap_NumBoards is less than MAXBOARDS, brd->SerialDriver should be >> >>>> registered. >> >>>> >> >>>> I'm not sure.. >> >>>> >> >>> >> >>> I don't see any check for (dgap_NumBoards < MAXBOARDS), which I think I >> >>> probably should, but I do see we are calling dgap_tty_register, which >> >>> can fail, without actually checking the return value. Also, yes, >> >>> dgap_Major_Xxxx_Registered seems to be always "false" until registered, >> >>> and it looks like dgap_Major_Xxxxx_Registered flags could be removed >> >>> because the only places we can unregister is at module_cleanup or >> >>> "after" it is already registered. >> >>> >> >>> What is the driver _supposed_ to do if we fail something on the second >> >>> or later board? Is the driver supposed to cleanup and exit or are we >> >>> supposed to stay loaded for the board/boards that are usable? >> >> >> >> Stay loaded. >> >> >> > >> > Then these tests on brd->dgap_Major_Serial_Registered need to stay in >> > there. If I have 3 boards and the second fails in some way, if I rmmod >> > the driver they will protect from unregistering a never registered one. >> > At least in the unregister code path. There is probably no need for them >> > in the register code path. I'll work up a patch for this. >> >> Should I update my patch? >> >> I think "if (!brd->dgap_Major_XXX_Registered)" line can be removed in this >> function, because if tty_register_driver() is failed just set "false" >> to "dgap_Major_XXX_Registered". > > Mark sent a patch to remove the check. Could you redo your patch based > on his? > > regards, > dan carpenter > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
