[PATCH RESEND] firmware: imx: SCU irq should ONLY be enabled after SCU IPC is ready

From: Anson Huang
Date: Sun May 12 2019 - 04:39:56 EST


The imx_scu_irq_group_enable() is normally called during module driver
probe phase to enable SCU group irq, if SCU IPC is NOT ready, below
dump will show out:

[ 0.933001] Hardware name: Freescale i.MX8QXP MEK (DT)
[ 0.938129] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 0.942907] pc : imx_scu_call_rpc+0x114/0x158
[ 0.947251] lr : imx_scu_irq_group_enable+0x74/0xc4
[ 0.952113] sp : ffff00001005bae0
[ 0.955415] x29: ffff00001005bae0 x28: ffff0000111bb0a0
[ 0.960712] x27: ffff00001140b000 x26: ffff00001111068c
[ 0.966011] x25: ffff0000111bb100 x24: 0000000000000000
[ 0.971311] x23: ffff0000113d9cd8 x22: 0000000000000001
[ 0.976610] x21: 0000000000000001 x20: ffff80083b51a410
[ 0.981909] x19: ffff000011259000 x18: 0000000000000480
[ 0.987209] x17: 000000000023ffb8 x16: 0000000000000010
[ 0.992508] x15: 000000000000023f x14: ffffffffffffffff
[ 0.997807] x13: 0000000000000018 x12: 0000000000000030
[ 1.003107] x11: 0000000000000003 x10: 0101010101010101
[ 1.008406] x9 : ffffffffffffffff x8 : 7f7f7f7f7f7f7f7f
[ 1.013706] x7 : fefefeff646c606d x6 : 0000000000000000
[ 1.019005] x5 : ffff0000112596c8 x4 : 0000000000000008
[ 1.024304] x3 : 0000000000000003 x2 : 0000000000000001
[ 1.029604] x1 : ffff00001005bb58 x0 : 0000000000000000
[ 1.034905] Call trace:
[ 1.037341] imx_scu_call_rpc+0x114/0x158
[ 1.041334] imx_scu_irq_group_enable+0x74/0xc4
[ 1.045856] imx_sc_wdt_probe+0x24/0x150
[ 1.049766] platform_drv_probe+0x4c/0xb0
[ 1.053762] really_probe+0x1f8/0x2c8
[ 1.057407] driver_probe_device+0x58/0xfc
[ 1.061490] device_driver_attach+0x68/0x70
[ 1.065660] __driver_attach+0x94/0xdc
[ 1.069397] bus_for_each_dev+0x64/0xc0
[ 1.073220] driver_attach+0x20/0x28
[ 1.076782] bus_add_driver+0x148/0x1fc
[ 1.080601] driver_register+0x68/0x120
[ 1.084424] __platform_driver_register+0x4c/0x54
[ 1.089120] imx_sc_wdt_driver_init+0x18/0x20
[ 1.093463] do_one_initcall+0x58/0x1b8
[ 1.097287] kernel_init_freeable+0x1cc/0x288
[ 1.101630] kernel_init+0x10/0x100
[ 1.105101] ret_from_fork+0x10/0x18
[ 1.108669] ---[ end trace 9e03302114457de9 ]---
[ 1.113296] enable irq failed, group 1, mask 1, ret -22

To avoid such scenario, return -EPROBE_DEFER in imx_scu_irq_group_enable()
API if SCU IPC is NOT ready, then module driver which calls this API
in probe phase will defer probe after SCU IPC ready.

Fixes: 851826c7566e ("firmware: imx: enable imx scu general irq function")
Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
---
No code change, just resend the patch with correct encoding.
---
drivers/firmware/imx/imx-scu-irq.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/firmware/imx/imx-scu-irq.c b/drivers/firmware/imx/imx-scu-irq.c
index 043833a..687121f 100644
--- a/drivers/firmware/imx/imx-scu-irq.c
+++ b/drivers/firmware/imx/imx-scu-irq.c
@@ -100,6 +100,9 @@ int imx_scu_irq_group_enable(u8 group, u32 mask, u8 enable)
struct imx_sc_rpc_msg *hdr = &msg.hdr;
int ret;

+ if (!imx_sc_irq_ipc_handle)
+ return -EPROBE_DEFER;
+
hdr->ver = IMX_SC_RPC_VERSION;
hdr->svc = IMX_SC_RPC_SVC_IRQ;
hdr->func = IMX_SC_IRQ_FUNC_ENABLE;
--
2.7.4