On 27/11/2017 08:48, Geert Uytterhoeven wrote: > The MDIO bus callback is not called from the network device ... > >>> smsc hangs of [fec10000.bus, which is started only here ---> >>> >>> Workqueue: events_power_efficient phy_state_machine >>> [<c010f304>] (unwind_backtrace) from [<c010b7ec>] (show_stack+0x10/0x14) >>> [<c010b7ec>] (show_stack) from [<c0551ab0>] (dump_stack+0xa4/0xdc) >>> [<c0551ab0>] (dump_stack) from [<c0120480>] (__warn+0xcc/0xfc) >>> [<c0120480>] (__warn) from [<c0120554>] (warn_slowpath_null+0x1c/0x24) >>> [<c0120554>] (warn_slowpath_null) from [<c03ce264>] >>> (__smsc911x_reg_read+0x1c/0x88) >>> [<c03ce264>] (__smsc911x_reg_read) from [<c03cefc8>] >>> (smsc911x_mac_read+0x4c/0x118) >>> [<c03cefc8>] (smsc911x_mac_read) from [<c03cf320>] >>> (smsc911x_mii_read+0x2c/0xa4) >>> [<c03cf320>] (smsc911x_mii_read) from [<c03cd490>] >>> (mdiobus_read+0x58/0x70) >>> [<c03cd490>] (mdiobus_read) from [<c03cc4a0>] >>> (genphy_update_link+0x18/0x50) >>> [<c03cc4a0>] (genphy_update_link) from [<c03cc4e4>] >>> (genphy_read_status+0xc/0x1cc) >>> [<c03cc4e4>] (genphy_read_status) from [<c03ca3e4>] >>> (phy_state_machine+0xa8/0x3f4) >>> [<c03ca3e4>] (phy_state_machine) from [<c013a740>] >>> (process_one_work+0x240/0x3fc) >>> [<c013a740>] (process_one_work) from [<c013af28>] >>> (worker_thread+0x2cc/0x40c) >>> [<c013af28>] (worker_thread) from [<c014024c>] (kthread+0x124/0x144) > > ... but from the worker thread, which is unaware of PM states, unless it is > a freezable workqueue. > > Cfr. my patch "[1/2] net: phy: Freeze PHY polling before suspending devices" > (https://patchwork.kernel.org/patch/9915901/), which made it a freezable > workqueue, like was done on PCI to solve similar issues with PME scanning.
Hello Geert, Florian, Is there something I can do to help this patch move forward? Should we look for a different solution than a synchronous call to phy_state_machine() ? (Or should I call it from the device driver, instead of expecting the phy framework to do it?) Regards.
