[PATCH] media: mtk-vpu: on suspend, read/write regs only if vpu is running

From: Dafna Hirschfeld
Date: Fri Apr 23 2021 - 13:27:59 EST


If the vpu is not running, we should not relay on VPU_IDLE_REG
value. In this case, the suspend cb should only unprepare the
clock. This fixes a system-wide suspend to ram failure:

[ 273.073363] PM: suspend entry (deep)
[ 273.410502] mtk-msdc 11230000.mmc: phase: [map:ffffffff] [maxlen:32] [final:10]
[ 273.455926] Filesystems sync: 0.378 seconds
[ 273.589707] Freezing user space processes ... (elapsed 0.003 seconds) done.
[ 273.600104] OOM killer disabled.
[ 273.603409] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[ 273.613361] mwifiex_sdio mmc2:0001:1: None of the WOWLAN triggers enabled
[ 274.784952] mtk_vpu 10020000.vpu: vpu idle timeout
[ 274.789764] PM: dpm_run_callback(): platform_pm_suspend+0x0/0x70 returns -5
[ 274.796740] mtk_vpu 10020000.vpu: PM: failed to suspend: error -5
[ 274.802842] PM: Some devices failed to suspend, or early wake event detected
[ 275.426489] OOM killer enabled.
[ 275.429718] Restarting tasks ...
[ 275.435765] done.
[ 275.447510] PM: suspend exit

Fixes: 1f565e263c3e ("media: mtk-vpu: VPU should be in idle state before system is suspended")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
---
drivers/media/platform/mtk-vpu/mtk_vpu.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/media/platform/mtk-vpu/mtk_vpu.c b/drivers/media/platform/mtk-vpu/mtk_vpu.c
index 043894f7188c..f49f6d53a941 100644
--- a/drivers/media/platform/mtk-vpu/mtk_vpu.c
+++ b/drivers/media/platform/mtk-vpu/mtk_vpu.c
@@ -987,6 +987,12 @@ static int mtk_vpu_suspend(struct device *dev)
return ret;
}

+ if (!vpu_running(vpu)) {
+ vpu_clock_disable(vpu);
+ clk_unprepare(vpu->clk);
+ return 0;
+ }
+
mutex_lock(&vpu->vpu_mutex);
/* disable vpu timer interrupt */
vpu_cfg_writel(vpu, vpu_cfg_readl(vpu, VPU_INT_STATUS) | VPU_IDLE_STATE,
--
2.17.1