On 23/11/16 07:49, Sekhar Nori wrote: > On Tuesday 22 November 2016 09:16 PM, Sudeep Holla wrote: >> Hi Sekhar, >> >> On 22/11/16 15:06, Sekhar Nori wrote: >>> Hi Sudeep, >>> >>> On Tuesday 22 November 2016 04:23 PM, Sudeep Holla wrote: >>>> >>>> >>>> On 22/11/16 10:41, Bartosz Golaszewski wrote: >>>>> Add a function allowing to retrieve the compatible string of the root >>>>> node of the device tree. >>>>> >>>> >>>> Rob has queued [1] and it's in -next today. You can reuse that if you >>>> are planning to target this for v4.11 or just use open coding in your >>>> driver for v4.10 and target this move for v4.11 to avoid cross tree >>>> dependencies as I already mentioned in your previous thread. >>> >>> I dont have your original patch in my mailbox, but I wonder if >>> returning a pointer to property string for a node whose reference has >>> already been released is safe to do? Probably not an issue for the root >>> node, but still feels counter-intuitive. >>> >> >> I am not sure if I understand the issue here. Are you referring a case >> where of_root is freed ? > > Yes, right, thats what I was hinting at. Since you are giving up the > reference to the device node before the function returns, the user can > be left with a dangling reference. >
Yes I agree. >> Also I have seen drivers today just using this pointer directly, but >> it's better to copy the string(I just saw this done in one case) > > Hmm, the reference is given up before the API returns, so I doubt > copying it later is any additional benefit. > True. > I suspect this is a theoretical issue though since root device node is > probably never freed. > Indeed, not sure if it's worth adding additional code to release the nod at all call sites. -- Regards, Sudeep
