From: "Zhiyong.Tao" <zhiyong.tao@xxxxxxxxxxxx> Fix pwrap FSM timeout issue which leads the system crash on GFX VSRAM power on. The crash log: [ 3986.543401] mediatek-drm-dp 1c500000.edp_tx: drm_helper_hpd_irq_event [ 3986.670756] vsram_others: is_enabled() failed: -ETIMEDOUT [ 3986.670765] mali 13000000.mali: Power on reg 1 failed error = -110 [ 3986.670768] ------------[ cut here ]------------ [ 3986.670770] unbalanced disables for vsram_others [ 3986.670783] WARNING: CPU: 7 PID: 4125 at drivers/regulator/core.c:2761 _regulator_disable+0x194/0x1a0 [ 3986.670785] Modules linked in: rfcomm algif_hash algif_skcipher af_alg veth uinput btusb btmtk btintel btbcm btrtl xt_cgroup bluetooth uvcvideo videobuf2_vmalloc ecdh_generic ecc mtk_vcodec_dec mtk_vcodec_enc mtk_mdp3 v4l2_h264 mtk_vcodec_common videobuf2_dma_contig mtk_vpu videobuf2_memops v4l2_mem2mem xt_MASQUERADE videobuf2_v4l2 videobuf2_common cros_ec_rpmsg mtk_scp mtk_rpmsg rpmsg_core mtk_scp_ipi ip6table_nat fuse 8021q iio_trig_sysfs cros_ec_sensors cros_ec_lid_angle cros_ec_sensors_core industrialio_triggered_buffer kfifo_buf cros_ec_sensorhub mt7921e mt7921_common mt76_connac_lib lzo_rle mt76 lzo_compress mac80211 cfg80211 zram r8152 mii joydev [ 3986.670830] CPU: 7 PID: 4125 Comm: mali-cmar-backe Not tainted 5.10.78-CL2781499-v287 #1 b899b40a63da40d4767c6c0e96b6700d2f3eb242 [ 3986.670832] Hardware name: MediaTek Tomato board (DT) [ 3986.670835] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--) [ 3986.670838] pc : _regulator_disable+0x194/0x1a0 [ 3986.670840] lr : _regulator_disable+0x194/0x1a0 [ 3986.670842] sp : ffffffc016203a10 [ 3986.670843] x29: ffffffc016203a10 x28: ffffffb7c3186b28 [ 3986.670846] x27: 0000000000000002 x26: fffffffffffffdc8 [ 3986.670848] x25: ffffffc017225000 x24: ffffffb7c0e94880 [ 3986.670851] x23: ffffffb7c31840f0 x22: ffffffd6b4f3e275 [ 3986.670853] x21: ffffffb7c3181a00 x20: ffffffb7c27e7800 [ 3986.670855] x19: ffffffb7c27e7800 x18: 00000000ffff0a10 [ 3986.670857] x17: 0000000000000020 x16: 00000000000000ec [ 3986.670860] x15: ffffffd6b44fa17c x14: 0000000000000003 [ 3986.670862] x13: 0000000000000004 x12: 0000000000fd8318 [ 3986.670864] x11: c000000100029ccd x10: 00000000ffffffff [ 3986.670866] x9 : 7dd6d080afd6f400 x8 : 7dd6d080afd6f400 [ 3986.670868] x7 : 0000000000000000 x6 : ffffffd6b5459f0c [ 3986.670871] x5 : ffffffc016203a58 x4 : 0000000000000000 [ 3986.670873] x3 : ffffffc016203668 x2 : ffffffc016203670 [ 3986.670875] x1 : 0000000100029ccd x0 : 0000000000000024 [ 3986.670878] Call trace: [ 3986.670880] _regulator_disable+0x194/0x1a0 [ 3986.670883] regulator_disable+0x4c/0x8c Add a usleep delay to avoid busy read for the H/W status. If (time_after()) be turn first, it maybe cause the system behavior crash problem like above. so we change it after sleep delay. Fixes: 1f022d84bd19 ("soc: mediatek: Add PMIC wrapper for MT8135 and MT8173 SoCs") Signed-off-by: Zhiyong.Tao <zhiyong.tao@xxxxxxxxxxxx> --- drivers/soc/mediatek/mtk-pmic-wrap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c index 952bc554f443..f9e7c2f35157 100644 --- a/drivers/soc/mediatek/mtk-pmic-wrap.c +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c @@ -4,6 +4,7 @@ * Author: Flora Fu, MediaTek */ #include <linux/clk.h> +#include <linux/delay.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> @@ -1197,10 +1198,13 @@ static int pwrap_wait_for_state(struct pmic_wrapper *wrp, timeout = jiffies + usecs_to_jiffies(10000); do { - if (time_after(jiffies, timeout)) - return fp(wrp) ? 0 : -ETIMEDOUT; if (fp(wrp)) return 0; + + usleep_range(10, 11); + + if (time_after(jiffies, timeout)) + return fp(wrp) ? 0 : -ETIMEDOUT; } while (1); } -- 2.18.0