On 09/22/2016 01:33 AM, Maciej S. Szmigiero wrote: > On 22.09.2016 00:45, Marek Vasut wrote: >> On 09/22/2016 12:18 AM, Maciej S. Szmigiero wrote: >>> On 21.09.2016 21:32, Marek Vasut wrote: >>>> On 09/21/2016 06:28 PM, Maciej S. Szmigiero wrote: >>>>> Hi Marek, >>>> >>>> Hi! >>>> >>>>> On 19.09.2016 21:30, Marek Vasut wrote: >>> (..) >>>>>> The RB-tree regmap cache needs to allocate new space on first >>>>>> writes. >>>>> >>>>> That's why SSI driver had .num_reg_defaults_raw set in regmap config. >>>>> With this set and .reg_defaults_raw unset regcache_hw_init() will read >>>>> existing register content which then will be used to populate cache >>>>> (and so allocate RB tree nodes) at regcache initialization time. >>>> >>>> OK >>>> >>>>> This means that allocation of new cache RB tree nodes should never happen >>>>> during actual write. >>>>> If you get a warning that it happened then maybe there is a write to >>>>> some register not covered by .num_reg_defaults_raw - this should be >>>>> fixed. >>>> >>>> I might be blind, but I really don't see that. I just discussed it with >>>> Mark and he thinks the same. I will revisit this one more time. >>> >>> Maybe it would be possible to get a backtrace when that warning was >>> generated so we know which register write or update triggers new cache >>> allocation? >> >> See patch 5/5 . > > In you patch 5/5 there is backtrace with flat cache, but I meant a > backtrace with original RB tree cache code when warning about allocation > being done in atomic context was generated. Here you go: > fsl-ssi-dai 202c000.ssi: No cache defaults, reading back from HW > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2871 lockdep_trace_alloc+0x104/0x128 > DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.4-00041-g0260041 #2 > Hardware name: Freescale i.MX6 SoloX (Device Tree) > Backtrace: > [<c010c188>] (dump_backtrace) from [<c010c380>] (show_stack+0x18/0x1c) > r7:00000000 r6:60000093 r5:00000000 r4:c0f1e77c > [<c010c368>] (show_stack) from [<c03f8184>] (dump_stack+0xb4/0xe8) > [<c03f80d0>] (dump_stack) from [<c0123638>] (__warn+0xd8/0x104) > r9:c016f054 r8:00000b37 r7:00000009 r6:c0c59f68 r5:00000000 r4:db453b10 > [<c0123560>] (__warn) from [<c01236a0>] (warn_slowpath_fmt+0x3c/0x44) > r9:00000012 r8:024000c0 r7:024000c0 r6:00000040 r5:024000c0 r4:c0c570f0 > [<c0123668>] (warn_slowpath_fmt) from [<c016f054>] (lockdep_trace_alloc+0x104/0x128) > r3:c0c5b07c r2:c0c570f0 > r4:60000093 > [<c016ef50>] (lockdep_trace_alloc) from [<c0215e24>] (__kmalloc_track_caller+0x44/0x230) > r5:024000c0 r4:db401e80 > [<c0215de0>] (__kmalloc_track_caller) from [<c01f01d0>] (krealloc+0x54/0xc0) > r10:00000058 r9:00000012 r8:c050d4f0 r7:024000c0 r6:00000040 r5:0000004c > r4:dacd7d80 > [<c01f017c>] (krealloc) from [<c050d4f0>] (regcache_rbtree_write+0x364/0x608) > r9:00000012 r8:00000004 r7:00000010 r6:dacd9a00 r5:dacd7d50 r4:00000010 > [<c050d18c>] (regcache_rbtree_write) from [<c050c230>] (regcache_write+0x5c/0x64) > r10:dacd9818 r9:dacd9964 r8:00000000 r7:dacd9a00 r6:000000ff r5:00000058 > r4:dacd9a00 > [<c050c1d4>] (regcache_write) from [<c050a3ac>] (_regmap_write+0x74/0x9c) > r7:dacd9a00 r6:000000ff r5:00000058 r4:dacd9a00 > [<c050a338>] (_regmap_write) from [<c050b5bc>] (regmap_write+0x44/0x64) > r7:00000006 r6:000000ff r5:00000058 r4:dacd9a00 > [<c050b578>] (regmap_write) from [<c0731090>] (_fsl_ssi_set_dai_fmt+0x31c/0x4fc) > r7:00000006 r6:00000000 r5:dacd9a00 r4:dacd9810 > [<c0730d74>] (_fsl_ssi_set_dai_fmt) from [<c0731f94>] (fsl_ssi_probe+0x58c/0x7b4) > r9:dacd9964 r8:00000000 r7:dbbbf164 r6:db4f0000 r5:db4f0010 r4:dacd9810 > [<c0731a08>] (fsl_ssi_probe) from [<c0501994>] (platform_drv_probe+0x3c/0x74) > r10:c0e00618 r9:00000000 r8:c0f608b4 r7:00000000 r6:c1753a70 r5:c0f608b4 > r4:db4f0010 > [<c0501958>] (platform_drv_probe) from [<c0500134>] (really_probe+0x1b8/0x264) > r5:c1753a68 r4:db4f0010 > [<c04fff7c>] (really_probe) from [<c05002b4>] (__driver_attach+0xd4/0xd8) > r9:c0e58858 r8:00000000 r7:00000000 r6:db4f0044 r5:c0f608b4 r4:db4f0010 > [<c05001e0>] (__driver_attach) from [<c04fe2c4>] (bus_for_each_dev+0x74/0xa8) > r7:00000000 r6:c05001e0 r5:c0f608b4 r4:00000000 > [<c04fe250>] (bus_for_each_dev) from [<c04ffaa4>] (driver_attach+0x20/0x28) > r6:c0f2ef08 r5:dacd6480 r4:c0f608b4 > [<c04ffa84>] (driver_attach) from [<c04ff5f4>] (bus_add_driver+0x104/0x214) > [<c04ff4f0>] (bus_add_driver) from [<c05008e0>] (driver_register+0x80/0xfc) > r7:c0d498e0 r6:c0e58850 r5:ffffe000 r4:c0f608b4 > [<c0500860>] (driver_register) from [<c0501944>] (__platform_driver_register+0x38/0x4c) > r5:ffffe000 r4:c0e4cdf8 > [<c050190c>] (__platform_driver_register) from [<c0e4ce10>] (fsl_ssi_driver_init+0x18/0x20) > [<c0e4cdf8>] (fsl_ssi_driver_init) from [<c0101924>] (do_one_initcall+0x44/0x178) > [<c01018e0>] (do_one_initcall) from [<c0e00e74>] (kernel_init_freeable+0x124/0x1e8) > r8:000000ed r7:c0d498e0 r6:c0e58850 r5:c0f6e000 r4:c0e6b590 > [<c0e00d50>] (kernel_init_freeable) from [<c0958080>] (kernel_init+0x10/0x11c) > r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c0958070 > r4:00000000 > [<c0958070>] (kernel_init) from [<c0107c70>] (ret_from_fork+0x14/0x24) > r5:c0958070 r4:00000000 > ---[ end trace 4907f763bc504c04 ]--- > imx-wm9712 sound: wm9712-hifi <-> 202c000.ssi mapping ok > wm9712-codec wm9712-codec: ASoC: mux Capture Phone Mux has no paths > wm9712-codec wm9712-codec: ASoC: mux Differential Source has no paths -- Best regards, Marek Vasut _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
