On Fri, Jan 10, 2014 at 07:13:11PM -0800, Dan Williams wrote: > On Fri, Jan 10, 2014 at 6:13 PM, Phillip Susi <psusi@xxxxxxxxxx> wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA512 > > > > On 01/10/2014 06:11 PM, Brandt, Todd E wrote: > >> Yes yours is simpler, but it also opens a potential memory issue > >> by passing a static int as the return location for the error value. > >> I think it's just safer to tell the callback to attempt no return > >> value at all, and for that you need to expand it into two > >> arguments, one for selection, the other for the output address. > > > > What sort of memory issue? Also isn't there a system NULL page > > somewhere that could be used? > > > > I think the static variable is ok. We can be sure that all eh threads > are torn down before libata.ko is unloaded. Actually there's one other reason. In the ata_port_request_pm function it checks to see if there's a previous resume operation pending, and if so it calls ata_port_wait_eh in order to wait for it to complete before issuing the new suspend. If you just use the (int*)async parameter it will return immediately and defer to the caller to try again, like is does with SAS. But in our case we *don't* try again, so it would result in the resume being skipped. There needs to be a new case where the caller wants the call to be asynchronous, and it wants ata_port_request_pm to do its own waiting, but doesn't care about the return value. Thus the additional parameter. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
