Nishanth Menon <nm@xxxxxx> wrote: > Chikkature Rajashekar, Madhusudhan had written, on 05/07/2010 11:59 AM, the > following: >> >>> >>>> -----Original Message----- >>>> From: Chikkature Rajashekar, Madhusudhan >>>> Sent: Thursday, May 06, 2010 9:50 PM >>>> To: Shilimkar, Santosh; 'kishore kadiyala' >>>> Cc: S, Venkatraman; linux-omap@xxxxxxxxxxxxxxx; linux- >>> >>> mmc@xxxxxxxxxxxxxxx; linux-arm- >>>> >>>> kernel@xxxxxxxxxxxxxxxxxxxxxx; 'Adrian Hunter'; Kadiyala, Kishore; 'Tony >>> >>> Lindgren' >>>> >>>> Subject: RE: [PATCH v8 2/2] omap hsmmc: adaptation of sdma descriptor >>> >>> autoloading feature >>>> >>>> >>>>> -----Original Message----- >>>>> From: Shilimkar, Santosh [mailto:santosh.shilimkar@xxxxxx] >>>>> Sent: Thursday, May 06, 2010 4:39 AM >>>>> To: kishore kadiyala >>>>> Cc: S, Venkatraman; linux-omap@xxxxxxxxxxxxxxx; linux- >>> >>> mmc@xxxxxxxxxxxxxxx; >>>>> >>>>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxxxxx; Chikkature Rajashekar, >>>>> Madhusudhan; Adrian Hunter; Kadiyala, Kishore; Tony Lindgren >>>>> Subject: RE: [PATCH v8 2/2] omap hsmmc: adaptation of sdma descriptor >>>>> autoloading feature >>>>> >>>>>> -----Original Message----- >>>>>> From: kishore kadiyala [mailto:kishorek.kadiyala@xxxxxxxxx] >>>>>> Sent: Thursday, May 06, 2010 2:32 PM >>>>>> To: Shilimkar, Santosh >>>>>> Cc: S, Venkatraman; linux-omap@xxxxxxxxxxxxxxx; linux- >>>>> >>>>> mmc@xxxxxxxxxxxxxxx; linux-arm- >>>>>> >>>>>> kernel@xxxxxxxxxxxxxxxxxxxxxx; Chikkature Rajashekar, Madhusudhan; >>>>> >>>>> Adrian Hunter; Kadiyala, Kishore; >>>>>> >>>>>> Tony Lindgren >>>>>> Subject: Re: [PATCH v8 2/2] omap hsmmc: adaptation of sdma >>> >>> descriptor >>>>> >>>>> autoloading feature >>>>>> >>>>>> <<snip>> >>>>>> >>>>>>>> I am not clear about the method. The board files export the >>>>>>>> omap_mmc_platform_data. >>>>>>>> Does it imply that all board files have to change and export >>>>>>>> the capability so that it can be queried ? >>>>>>> >>>>>>> No. You don't have to modify the board files. This would need >>>>>>> change in devices.c which common for all omap boards. >>>>>>> >>>>>>> I don't have a strong opinion on this point but just put forth an >>>>>>> alternate way to avoid such SOC specific check in drivers. >>>>>>> You can take call on this >>>>>> >>>>>> Agree. How about adding a flag in hsmmc.h & omap_mmc_platform_data, >>>>>> that would take care of SDMA & SDMA_DLAOD in the driver instead >>> >>> going >>>>>> >>>>>> with SOC check . >>>>> >>>>> Good idea Kishore. >>>>> Venkat, >>>>> Can you do what kishore is suggesting. >>>>> >>>> omap_mmc_platform_data is MMC specific platform data. Why add a SDMA >>>> specific feature capability into it? Even though you add it there, you >>> >>> will >>>> >>>> still need to have a cpu check before that can be set in a common code. >>>> >>> CPU checks are allowed to be in the platform files. That is where such >>> machine/SOC specific differentiation should be done and not in the device >>> drivers. >>> That way device drivers remains clean and portable. >>> >>> I want to stop this thread here since neither the patch author nor the >>> file >>> maintainer thinks that cpu checks in the device drivers is bad idea. >>> >>> Please decide within yourself and move on. >>> >> >> I am not saying that it is wrong. My point here is that adding this >> particular flag into MMC platform data to differentiate a SDMA specific >> feature which got introduced post certain SOC may not be needed. But you >> can >> always post your comments on the list which will be looked at by a wider >> audience and finally the right patch will go in. > > Please see [1] for SOC specific feature handling. any reasons we can't > handle it by adding a new feature? > > [1] > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=arch/arm/plat-omap/include/plat/cpu.h#l439 > Thanks. I can add a new feature here, but I see that the API is tied to OMAP3, whereas the DMA feature is common to 3630, OMAP4 and mostly everything after that. I can work on an upgrade, but do you see that as a dependency and done on the context of this patch ? Regards, Venkat. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
