On Tue, 25 Jan 2011, walter harms wrote: > > > Am 25.01.2011 11:43, schrieb Russell King - ARM Linux: > > On Tue, Jan 25, 2011 at 11:33:16AM +0100, walter harms wrote: > >> Would it be more easy to return NULL in the error case of clk_get() instead > >> of ERR_PTR(-ENOENT) ? > >> > >> So the default could be return NULL and an architecture depending solution > >> replacing that. > > > > That's not how the API is defined. The API defines error-pointers to be > > errors, everything should be considered valid. Please don't go down the > > route of doing something architecturally different from that. > > > > What if, say, you couldn't return the struct clk because maybe it could > > only be controlled by one user? Returning an EBUSY error pointer would > > indicate this condition. What if the module providing the struct clk > > hasn't finished initializing - that's another reason for EBUSY rather > > than ENOENT. > > > > Error codes are useful to describe why something failed. NULL pointers > > can't do that. > > > > On Mon, 24 Jan 2011, Vasiliy Kulikov wrote: > > > ... > > clk_get() is defined per-architecture, sometimes it is NULL only. > > > > So these is a bug ? They should return -ENOENT ? > > The interessting question is: what to do with an error ? > > Obviously some architecture can live with NULL, so it is not an critical > error. An the patch shows a code that is simply a return, not even the > user is informed that something did not work as expected. > > From that point of view i would like question if it is useful to have > a "detailed" error instead of just returning NULL. Somewhat unrelatedly, I often run into code where error handling code is needed, but not present, and the function returns void, so nothing is provided for propagating the error further. I generally consider these cases to be beyond my expertise to fix... julia -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
