On 26-11-2018 15:34, Thierry Reding wrote: > On Fri, Nov 23, 2018 at 12:44:02PM +0000, Jose Abreu wrote: >> On 23-11-2018 12:21, Thierry Reding wrote: >>> From: Thierry Reding <treding@xxxxxxxxxx> >>> >>> Setting up and tearing down debugfs is current unbalanced, as seen by >>> this error during resume from suspend: >>> >>> [ 752.134067] dwc-eth-dwmac 2490000.ethernet eth0: ERROR failed to create debugfs directory >>> [ 752.134347] dwc-eth-dwmac 2490000.ethernet eth0: stmmac_hw_setup: failed debugFS registration >>> >>> The imbalance happens because the driver creates the debugfs hierarchy >>> when the device is opened and tears it down when the device is closed. >>> There's little gain in that, and it could be argued that it is even >>> surprising because it's not usually done for other devices. Fix the >>> imbalance by moving the debugfs creation and teardown to the driver's >>> ->probe() and ->remove() implementations instead. >>> >>> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> >>> --- >>> >> Did you test trying to dump "descriptors_status" file when >> interface is not open ? I think that's the main reason why this >> is not in probe ... > Indeed, that seems to cause a hang. Still, it doesn't sound like the > right things to repeatedly create and remove debugfs files just because > we can't provide the contents when the device is down. Agree. > > How about we return an empty file or an error code instead when the > interface is down? I think an error code would be more suitable (ENODEV/EBUSY ?). Can you submit v2 ? Thanks and Best Regards, Jose Miguel Abreu > > Thierry
