[PATCH] clk: samsung: exynos5420: Keep top G3D clocks enabled

[Marek Szyprowski <m.szyprowski@samsung.com>]

All top clocks on G3D path has to be enabled all the time to allow proper
G3D power domain operation. This is achieved by adding CRITICAL flag to
"mout_sw_aclk_g3d" clock, what keeps this clock and all its parents
enabled.

This fixes following imprecise abort issue observed on Odroid XU3/XU4
after enabling Panfrost driver by commit 1a5a85c56402 "ARM: dts: exynos:
Add Mali/GPU node on Exynos5420 and enable it on Odroid XU3/4"):

panfrost 11800000.gpu: clock rate = 400000000
panfrost 11800000.gpu: failed to get regulator: -517
panfrost 11800000.gpu: regulator init failed -517
Power domain G3D disable failed
...
panfrost 11800000.gpu: clock rate = 400000000
8<--- cut here ---
Unhandled fault: imprecise external abort (0x1406) at 0x00000000
pgd = (ptrval)
[00000000] *pgd=00000000
Internal error: : 1406 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 7 PID: 53 Comm: kworker/7:1 Not tainted 5.4.0-rc8-next-20191119-00032-g56f1001191a6 #6923
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
PC is at panfrost_gpu_soft_reset+0x94/0x110
LR is at ___might_sleep+0x128/0x2dc
...
[<c05c231c>] (panfrost_gpu_soft_reset) from [<c05c2704>] (panfrost_gpu_init+0x10/0x67c)
[<c05c2704>] (panfrost_gpu_init) from [<c05c15d0>] (panfrost_device_init+0x158/0x2cc)
[<c05c15d0>] (panfrost_device_init) from [<c05c0cb0>] (panfrost_probe+0x80/0x178)
[<c05c0cb0>] (panfrost_probe) from [<c05cfaa0>] (platform_drv_probe+0x48/0x9c)
[<c05cfaa0>] (platform_drv_probe) from [<c05cd20c>] (really_probe+0x1c4/0x474)
[<c05cd20c>] (really_probe) from [<c05cd694>] (driver_probe_device+0x78/0x1bc)
[<c05cd694>] (driver_probe_device) from [<c05cb374>] (bus_for_each_drv+0x74/0xb8)
[<c05cb374>] (bus_for_each_drv) from [<c05ccfa8>] (__device_attach+0xd4/0x16c)
[<c05ccfa8>] (__device_attach) from [<c05cc110>] (bus_probe_device+0x88/0x90)
[<c05cc110>] (bus_probe_device) from [<c05cc634>] (deferred_probe_work_func+0x4c/0xd0)
[<c05cc634>] (deferred_probe_work_func) from [<c0149df0>] (process_one_work+0x300/0x864)
[<c0149df0>] (process_one_work) from [<c014a3ac>] (worker_thread+0x58/0x5a0)
[<c014a3ac>] (worker_thread) from [<c0151174>] (kthread+0x12c/0x160)
[<c0151174>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20)
Exception stack(0xee03dfb0 to 0xee03dff8)
...
Code: e594300c e5933020 e3130c01 1a00000f (ebefff50).
---[ end trace badde2b74a65a540 ]---

In the above case, the Panfrost driver disables G3D clocks after failure
of getting the needed regulator and return with -EPROVE_DEFER code. This
causes G3D power domain disable failure and then, during second probe
an imprecise abort is triggered due to undefined power domain state.

Fixes: 45f10dabb56b ("clk: samsung: exynos5420: Add SET_RATE_PARENT flag to clocks on G3D path")
Fixes: c9f7567aff31 ("clk: samsung: exynos542x: Move G3D subsystem clocks to its sub-CMU")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/clk/samsung/clk-exynos5420.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 3a991ca1ee36..89126ba66995 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -712,7 +712,7 @@ static const struct samsung_mux_clock exynos5x_mux_clks[] __initconst = {
 	MUX(0, "mout_sw_aclk266_g2d", mout_sw_aclk266_g2d_p,
 			SRC_TOP12, 12, 1),
 	MUX_F(0, "mout_sw_aclk_g3d", mout_sw_aclk_g3d_p, SRC_TOP12, 16, 1,
-	      CLK_SET_RATE_PARENT, 0),
+	      CLK_IS_CRITICAL | CLK_SET_RATE_PARENT, 0),
 	MUX(0, "mout_sw_aclk300_jpeg", mout_sw_aclk300_jpeg_p,
 			SRC_TOP12, 20, 1),
 	MUX(CLK_MOUT_SW_ACLK300, "mout_sw_aclk300_disp1",
-- 
2.17.1