On Tue, 2012-10-09 at 14:02 -0700, Andrew Morton wrote: > On Mon, 08 Oct 2012 11:07:20 -0600 > Shuah Khan <shuah.khan@xxxxxx> wrote: > > > > > > > Still seems overly complicated to me, but whatev. > > > > > > I think the way to handle this is pretty simple: set a flag in the dma > > > entry when someone runs dma_mapping_error() and, if that flag wasn't > > > set at unmap time, emit a loud warning. > > > > > > From my reading of the code, this patch indeed does that, along with a > > > bunch of other (unnecessary?) stuff. But boy, the changelog conceals > > > this information well! > > > > Are you referring to the system wide error counters when you say > > unnecessary stuff. The reason I added those was to catch errors when > > drivers don't do unmap. Several drivers fail to do unmap. Checking flag > > from unmap debug interfaces, doesn't cover these cases. However, I think > > the value of system wide counters is limited in the sense that they > > don't really identify the driver that needs fixing. In that sense it can > > be deemed unnecessary. I dropped them in v5 patch, which I am sending > > out. > > hm. Could we keep a counter of the number of map/unmap calls within > the dma object and then emit a warning if that is non-zero at teardown > time? That should identify the offending driver. > Thanks. That would work. Will take a look and see what it takes to implement. -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
