From a9e5f5eefd6b57f9fc6ac57a4bccc2be71aae4c8 Mon Sep 17 00:00:00 2001
From: Shuai Li <shuai.li@amlogic.com>
Date: Tue, 5 Nov 2019 14:47:37 +0800
Subject: [PATCH] audio: fix might_sleep warning at bootup [1/1]

PD#SWPL-16123

Problem:
might_sleep() is triggered by regmap_read().

[    3.106894@0] Workqueue: events tl1_acodec_release_fast_mode_work_func
[    3.106903@0] [bc059af4+  16][<c020e3a8>] show_stack+0x20/0x24
[    3.106910@0] [bc059b1c+  40][<c05dff94>] dump_stack+0xb8/0xf4
[    3.106917@0] [bc059b44+  40][<c0258138>] ___might_sleep+0x1c8/0x208
[    3.106922@0] [bc059b6c+  40][<c02581ec>] __might_sleep+0x74/0xac
[    3.106928@0] [bc059bb4+  72][<c0393a80>] kmem_cache_alloc_trace+0x12c/0x2c0
[    3.106935@0] [bc059bfc+  72][<c06bd03c>] regcache_rbtree_write+0x2dc/0x4f0
[    3.106941@0] [bc059c1c+  32][<c06bbbd8>] regcache_write+0x64/0x6c
[    3.106945@0] [bc059c44+  40][<c06b9260>] _regmap_write+0x144/0x16c
[    3.106948@0] [bc059c64+  32][<c06bab4c>] regmap_write+0x4c/0x6c
[    3.106953@0] [bc059c74+  16][<c0c79088>] snd_soc_component_write+0x28/0x48
[    3.106958@0] [bc059c84+  16][<c0c790c4>] snd_soc_write+0x1c/0x20
[    3.106962@0] [bc059c9c+  24][<c0c7c0b0>] tl1_acodec_start_up+0x24/0x44
[    3.106967@0] [bc059cbc+  32][<c0c7c1b8>]
tl1_acodec_release_fast_mode_work_func+0x54/0xe4
[    3.106973@0] [bc059cfc+  64][<c0245dc8>] process_one_work+0x200/0x624
[    3.106977@0] [bc059d3c+  64][<c0246dc4>] worker_thread+0x58/0x5c4
[    3.106982@0] [bc059d94+  88][<c024c5c0>] kthread+0x128/0x144
[    3.106987@0] [00000000+   0][<c020885c>] ret_from_fork+0x14/0x38

Solution:
This is a mmio regmap constrain using spinlock_irq to protect the
critical read and write.
But if the default reg cache is not allocated, the read routine will
malloc() buffer which is non-atomic. That is the root cause of this warning.
So we add num_reg_defaults_raw to tell regmap to malloc the buffer at
initializing stage.

Verify:
TL1.

Change-Id: I42f87fa89bbe99762ada36337b5ed6565b06b891
Signed-off-by: Shuai Li <shuai.li@amlogic.com>
---
 sound/soc/codecs/amlogic/aml_codec_tl1_acodec.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/codecs/amlogic/aml_codec_tl1_acodec.c b/sound/soc/codecs/amlogic/aml_codec_tl1_acodec.c
index 604c62f9abf6..dc5bd8bd9419 100644
--- a/sound/soc/codecs/amlogic/aml_codec_tl1_acodec.c
+++ b/sound/soc/codecs/amlogic/aml_codec_tl1_acodec.c
@@ -699,6 +699,7 @@ static const struct regmap_config tl1_acodec_regmap_config = {
 	.reg_stride = 4,
 	.val_bits = 32,
 	.max_register = 0x1c,
+	.num_reg_defaults_raw = ARRAY_SIZE(tl1_acodec_init_list),
 	.cache_type = REGCACHE_RBTREE,
 };