On Tue, Jul 28, 2015 at 10:13:54PM -0500, Rob Herring wrote: > On Tue, Jul 28, 2015 at 3:23 PM, Belisko Marek <marek.belisko@xxxxxxxxx> wrote: > > Hi Dmitry, > > > > On Thu, Jul 23, 2015 at 10:53 PM, Dmitry Torokhov > > <dmitry.torokhov@xxxxxxxxx> wrote: > >> On Thu, Jul 23, 2015 at 10:38:34PM +0200, Marek Belisko wrote: > >>> Fix following: > >>> [ 8.862274] ERROR: Bad of_node_put() on /ocp/i2c@48070000/twl@48/audio > >>> [ 8.869293] CPU: 0 PID: 1003 Comm: modprobe Not tainted 4.2.0-rc2-letux+ #1175 > >>> [ 8.876922] Hardware name: Generic OMAP36xx (Flattened Device Tree) > >>> [ 8.883514] [<c00159e0>] (unwind_backtrace) from [<c0012488>] (show_stack+0x10/0x14) > >>> [ 8.891693] [<c0012488>] (show_stack) from [<c05cb810>] (dump_stack+0x78/0x94) > >>> [ 8.899322] [<c05cb810>] (dump_stack) from [<c02cfd5c>] (kobject_release+0x68/0x7c) > >>> [ 8.907409] [<c02cfd5c>] (kobject_release) from [<bf0040c4>] (twl4030_vibra_probe+0x74/0x188 [twl4030_vibra]) > >>> [ 8.917877] [<bf0040c4>] (twl4030_vibra_probe [twl4030_vibra]) from [<c03816ac>] (platform_drv_probe+0x48/0x90) > >>> [ 8.928497] [<c03816ac>] (platform_drv_probe) from [<c037feb4>] (really_probe+0xd4/0x238) > >>> [ 8.937103] [<c037feb4>] (really_probe) from [<c0380160>] (driver_probe_device+0x30/0x48) > >>> [ 8.945678] [<c0380160>] (driver_probe_device) from [<c03801e0>] (__driver_attach+0x68/0x8c) > >>> [ 8.954589] [<c03801e0>] (__driver_attach) from [<c037ea60>] (bus_for_each_dev+0x50/0x84) > >>> [ 8.963226] [<c037ea60>] (bus_for_each_dev) from [<c037f828>] (bus_add_driver+0xcc/0x1e4) > >>> [ 8.971832] [<c037f828>] (bus_add_driver) from [<c0380b60>] (driver_register+0x9c/0xe0) > >>> [ 8.980255] [<c0380b60>] (driver_register) from [<c00097e0>] (do_one_initcall+0x100/0x1b8) > >>> [ 8.988983] [<c00097e0>] (do_one_initcall) from [<c00b8008>] (do_init_module+0x58/0x1c0) > >>> [ 8.997497] [<c00b8008>] (do_init_module) from [<c00b8cac>] (SyS_init_module+0x54/0x64) > >>> [ 9.005950] [<c00b8cac>] (SyS_init_module) from [<c000ed20>] (ret_fast_syscall+0x0/0x54) > >>> [ 9.015838] input: twl4030:vibrator as /devices/platform/68000000.ocp/48070000.i2c/i2c-0/0-0048/48070000.i2c:twl@48:audio/input/input2 > >>> > >>> node passed to of_find_node_by_name is put inside that function and new node > >>> is returned if found. Free returned node not already freed node. > >> > >> Hmm, if of_find_node_by_name() "puts" passed in node should we not "get" > >> it before calling of_find_node_by_name()? The node pointer in question > >> is simply copied from parent device. > > I'm not sure. what I can say is that I cannot see such error in 4.1 > > but only in 4.2-rcx. > > Adding Grant and Rob to CC, maybe they know what should be done and > > why I see such error in 4.2-rcx. > > The problem was that node passed into of_find_node_by_name is the the > starting point to search, but you should be doing the put on the > returned node. So the patch below is correct. > > As far as why in 4.2, it seems you have OF_DYNAMIC enabled in your > config either because you have DT unit test or overlays enabled. > Overlays are now user enable-able in 4.2. Right, but the question was whether we should also "get" the node that we are passing into of_find_node_by_name(), or, maybe better, stop of_find_node_by_name() from "putting" the node that is passed in? It is really surprising behavior. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
