[v2] mfd: intel-lpss: Set the device in reset state when init

[Binbin Wu <binbin.wu@intel.com>]

In virtualized setup, when system reboots due to warm
reset interrupt storm is seen.

Call Trace:
<IRQ>
dump_stack+0x70/0xa5
__report_bad_irq+0x2e/0xc0
note_interrupt+0x248/0x290
? add_interrupt_randomness+0x30/0x220
handle_irq_event_percpu+0x54/0x80
handle_irq_event+0x39/0x60
handle_fasteoi_irq+0x91/0x150
handle_irq+0x108/0x180
do_IRQ+0x52/0xf0
common_interrupt+0xf/0xf
</IRQ>
RIP: 0033:0x76fc2cfabc1d
Code: 24 28 bf 03 00 00 00 31 c0 48 8d 35 63 77 0e 00 48 8d 15 2e
94 0e 00 4c 89 f9 49 89 d9 4c 89 d3 e8 b8 e2 01 00 48 8b 54 24 18
<48> 89 ef 48 89 de 4c 89 e1 e8 d5 97 01 00 84 c0 74 2d 48 8b 04
24
RSP: 002b:00007ffd247c1fc0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffffda
RAX: 0000000000000000 RBX: 00007ffd247c1ff0 RCX: 000000000003d3ce
RDX: 0000000000000000 RSI: 00007ffd247c1ff0 RDI: 000076fc2cbb6010
RBP: 000076fc2cded010 R08: 00007ffd247c2210 R09: 00007ffd247c22a0
R10: 000076fc29465470 R11: 0000000000000000 R12: 00007ffd247c1fc0
R13: 000076fc2ce8e470 R14: 000076fc27ec9960 R15: 0000000000000414
handlers:
[<000000000d3fa913>] idma64_irq
Disabling IRQ #27

To avoid interrupt storm, set the device in reset state
before bringing out the device from reset state.

Changelog v2:
- correct the subject line by adding "mfd: "

Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/mfd/intel-lpss.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
index 50bffc3..ff3fba1 100644
--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -273,6 +273,9 @@ static void intel_lpss_init_dev(const struct intel_lpss *lpss)
 {
 	u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
 
+	/* Set the device in reset state */
+	writel(0, lpss->priv + LPSS_PRIV_RESETS);
+
 	intel_lpss_deassert_reset(lpss);
 
 	intel_lpss_set_remap_addr(lpss);