On Thu, Aug 12, 2010 at 12:57:18AM +0530, DebBarma, Tarun Kanti wrote: > > > -----Original Message----- > > From: Felipe Balbi [mailto:felipe.balbi@xxxxxxxxx] > > Sent: Thursday, August 12, 2010 12:27 AM > > To: DebBarma, Tarun Kanti > > Cc: Balbi Felipe (Nokia-MS/Helsinki); Ohad Ben-Cohen; linux- > > wireless@xxxxxxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; linux- > > omap@xxxxxxxxxxxxxxx; Ido Yariv; Mark Brown; linux-arm- > > kernel@xxxxxxxxxxxxxxxxxxx; Chikkature Rajashekar, Madhusudhan; Coelho > > Luciano (Nokia-MS/Helsinki); akpm@xxxxxxxxxxxxxxxxxxxx; San Mehat; Quadros > > Roger (Nokia-MS/Helsinki); Tony Lindgren; Nicolas Pitre; Pandita, Vikram; > > Kalle Valo > > Subject: Re: [PATCH v4 3/8] wireless: wl1271: add platform driver to get > > board data > > > > Hi, > > > > On Wed, Aug 11, 2010 at 08:52:54PM +0200, ext DebBarma, Tarun Kanti wrote: > > >True; however if we go by that argument than we can also assume pdata > > >is valid, so that we would not need the below check. > > > > of course not. You can have devices that just play well with default > > values or devices where you don't need the flexibility of platform data. > > That's why we check. > > > > platform_device pointers on the other hand, are guaranteed to be always > > true, if it isn't then you should oops, you deserve to oops because > > something is really really wrong. > > > Sounds perfect! > What that means is _probe() function makes sense only for cases where we > have valid platform data because we are returning right at the top if > pdata is not valid. If this is the case I was curious to know why not > framework make another check for valid pdata before calling _probe() > instead of coming all the way to _probe() and then returning! Platform devices are not for passing platform data around - they're for declaring platform hardware devices that we want drivers to handle - and it depends on the driver whether having platform data is appropriate or not. This proposal is, IMHO, abusing the platform device/driver support to achieve its own goals. I've outlined a far simpler and easiler solution which avoids this kind of abuse, and given suggestions on how to extend it to support multiple instances. -- 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
