On 04/19/2016 07:05 PM, Marek Vasut wrote: > Both socfpga_dwmac_parse_data() in dwmac-socfpga.c and stmmac_dvr_probe() > in stmmac_main.c functions call devm_reset_control_get() to register an > reset controller for the stmmac. This results in an attempt to register > two reset controllers for the same non-shared reset line. > > The first attempt to register the reset controller works fine. The second > attempt fails with warning from the reset controller core, see below. > The warning is produced because the reset line is non-shared and thus > it is allowed to have only up-to one reset controller associated with > that reset line, not two or more. > > The solution is not great. Since the hardware needs to toggle the reset > before calling stmmac_dvr_probe() to perform mandatory preconfiguration, > this patch splits socfpga_dwmac_init_probe() from socfpga_dwmac_init(). > > The socfpga_dwmac_init_probe() temporarily registers the reset controller, > performs the pre-configuration and unregisters the reset controller again. > This function is only called from the socfpga_dwmac_probe(). > > The original socfpga_dwmac_init() is tweaked to use reset controller > pointer from the stmmac_priv (private data of the stmmac core) instead > of the local instance, which was used before. > > Finally, plat_dat->exit and socfpga_dwmac_exit() is no longer necessary, > since the functionality is already performed by the stmmac core. > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at drivers/reset/core.c:187 > __of_reset_control_get+0x218/0x270 > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted > 4.6.0-rc4-next-20160419-00015-gabb2477-dirty #4 > Hardware name: Altera SOCFPGA > [<c010f290>] (unwind_backtrace) from [<c010b82c>] (show_stack+0x10/0x14) > [<c010b82c>] (show_stack) from [<c0373da4>] (dump_stack+0x94/0xa8) > [<c0373da4>] (dump_stack) from [<c011bcc0>] (__warn+0xec/0x104) > [<c011bcc0>] (__warn) from [<c011bd88>] (warn_slowpath_null+0x20/0x28) > [<c011bd88>] (warn_slowpath_null) from [<c03a6eb4>] > (__of_reset_control_get+0x218/0x270) > [<c03a6eb4>] (__of_reset_control_get) from [<c03a701c>] > (__devm_reset_control_get+0x54/0x90) > [<c03a701c>] (__devm_reset_control_get) from [<c041fa30>] > (stmmac_dvr_probe+0x1b4/0x8e8) > [<c041fa30>] (stmmac_dvr_probe) from [<c04298c8>] > (socfpga_dwmac_probe+0x1b8/0x28c) > [<c04298c8>] (socfpga_dwmac_probe) from [<c03d6ffc>] > (platform_drv_probe+0x4c/0xb0) > [<c03d6ffc>] (platform_drv_probe) from [<c03d54ec>] > (driver_probe_device+0x224/0x2bc) > [<c03d54ec>] (driver_probe_device) from [<c03d5630>] > (__driver_attach+0xac/0xb0) > [<c03d5630>] (__driver_attach) from [<c03d382c>] (bus_for_each_dev+0x6c/0xa0) > [<c03d382c>] (bus_for_each_dev) from [<c03d4ad4>] (bus_add_driver+0x1a4/0x21c) > [<c03d4ad4>] (bus_add_driver) from [<c03d60ac>] (driver_register+0x78/0xf8) > [<c03d60ac>] (driver_register) from [<c0101760>] (do_one_initcall+0x40/0x170) > [<c0101760>] (do_one_initcall) from [<c0800e38>] > (kernel_init_freeable+0x1dc/0x27c) > [<c0800e38>] (kernel_init_freeable) from [<c05d1bd4>] (kernel_init+0x8/0x114) > [<c05d1bd4>] (kernel_init) from [<c01076f8>] (ret_from_fork+0x14/0x3c) > ---[ end trace 059d2fbe87608fa9 ]--- >
Odd, I hadn't seen this error before. I would have noticed it, but I haven't ran linux-next for a few days. I see that this error was introduced on linux-next/next-20160414. The error was not there prior to that. While I agree that the extra call to get the reset control is not needed, I wonder what commit between next-20160413 and next-20160414 exposed this error. I'll try to dig this some more. Dinh