wlcore: Fixup "Add support for optional wakeirq"

After commit 3c83dd5 ("wlcore: Add support for optional
wakeirq") landed upstream, I started seeing the following oops
on my HiKey board:

[    1.870279] Unable to handle kernel read from unreadable memory at virtual address 0000000000000010
[    1.870283] Mem abort info:
[    1.870287]   ESR = 0x96000005
[    1.870292]   Exception class = DABT (current EL), IL = 32 bits
[    1.870296]   SET = 0, FnV = 0
[    1.870299]   EA = 0, S1PTW = 0
[    1.870302] Data abort info:
[    1.870306]   ISV = 0, ISS = 0x00000005
[    1.870309]   CM = 0, WnR = 0
[    1.870312] [0000000000000010] user address but active_mm is swapper
[    1.870318] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[    1.870327] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 4.19.0-05129-gb3d1e8e #48
[    1.870331] Hardware name: HiKey Development Board (DT)
[    1.870350] Workqueue: events_freezable mmc_rescan
[    1.870358] pstate: 60400005 (nZCv daif +PAN -UAO)
[    1.870366] pc : wl1271_probe+0x210/0x350
[    1.870371] lr : wl1271_probe+0x210/0x350
[    1.870374] sp : ffffff80080739b0
[    1.870377] x29: ffffff80080739b0 x28: 0000000000000000
[    1.870384] x27: 0000000000000000 x26: 0000000000000000
[    1.870391] x25: 0000000000000036 x24: ffffffc074ecb598
[    1.870398] x23: ffffffc07ffdce78 x22: ffffffc0744ed808
[    1.870404] x21: ffffffc074ecbb98 x20: ffffff8008ff9000
[    1.870411] x19: ffffffc0744ed800 x18: ffffff8008ff9a48
[    1.870418] x17: 0000000000000000 x16: 0000000000000000
[    1.870425] x15: ffffffc074ecb503 x14: ffffffffffffffff
[    1.870431] x13: ffffffc074ecb502 x12: 0000000000000030
[    1.870438] x11: 0101010101010101 x10: 0000000000000040
[    1.870444] x9 : ffffffc075400248 x8 : ffffffc075400270
[    1.870451] x7 : 0000000000000000 x6 : 0000000000000000
[    1.870457] x5 : 0000000000000000 x4 : 0000000000000000
[    1.870463] x3 : 0000000000000000 x2 : 0000000000000000
[    1.870469] x1 : 0000000000000028 x0 : 0000000000000000
[    1.870477] Process kworker/0:0 (pid: 5, stack limit = 0x(____ptrval____))
[    1.870480] Call trace:
[    1.870485]  wl1271_probe+0x210/0x350
[    1.870491]  sdio_bus_probe+0x100/0x128
[    1.870500]  really_probe+0x1a8/0x2b8
[    1.870506]  driver_probe_device+0x58/0x100
[    1.870511]  __device_attach_driver+0x94/0xd8
[    1.870517]  bus_for_each_drv+0x70/0xc8
[    1.870522]  __device_attach+0xe0/0x140
[    1.870527]  device_initial_probe+0x10/0x18
[    1.870532]  bus_probe_device+0x94/0xa0
[    1.870537]  device_add+0x374/0x5b8
[    1.870542]  sdio_add_func+0x60/0x88
[    1.870546]  mmc_attach_sdio+0x1b0/0x358
[    1.870551]  mmc_rescan+0x2cc/0x390
[    1.870558]  process_one_work+0x12c/0x320
[    1.870563]  worker_thread+0x48/0x458
[    1.870569]  kthread+0xf8/0x128
[    1.870575]  ret_from_fork+0x10/0x18
[    1.870583] Code: 92400c21 b2760021 a90687a2 97e95bf9 (f9400803)
[    1.870587] ---[ end trace 1e15f81d3c139ca9 ]---

It seems since we don't have a wakeirq value in the dts, the wakeirq
value in wl1271_probe() is zero, which then causes trouble in
irqd_get_trigger_type(irq_get_irq_data(wakeirq)).

This patch tries to address this by checking if wakeirq is zero,
and not trying to add it to the resources if that is the case.

Fixes: 3c83dd5 ("wlcore: Add support for optional wakeirq")
Cc: Tony Lindgren <tony@atomide.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Eyal Reizer <eyalr@ti.com>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: linux-wireless@vger.kernel.org
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ti/wlcore/sdio.c

@@ -285,7 +285,7 @@ static int wl1271_probe(struct sdio_func *func,
 	struct resource res[2];
 	mmc_pm_flag_t mmcflags;
 	int ret = -ENOMEM;
-	int irq, wakeirq;
+	int irq, wakeirq, num_irqs;
 	const char *chip_family;
 
 	/* We are only able to handle the wlan function */
@@ -353,12 +353,17 @@ static int wl1271_probe(struct sdio_func *func,
 		       irqd_get_trigger_type(irq_get_irq_data(irq));
 	res[0].name = "irq";
 
-	res[1].start = wakeirq;
-	res[1].flags = IORESOURCE_IRQ |
-		       irqd_get_trigger_type(irq_get_irq_data(wakeirq));
-	res[1].name = "wakeirq";
 
-	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
+	if (wakeirq > 0) {
+		res[1].start = wakeirq;
+		res[1].flags = IORESOURCE_IRQ |
+			       irqd_get_trigger_type(irq_get_irq_data(wakeirq));
+		res[1].name = "wakeirq";
+		num_irqs = 2;
+	} else {
+		num_irqs = 1;
+	}
+	ret = platform_device_add_resources(glue->core, res, num_irqs);
 	if (ret) {
 		dev_err(glue->dev, "can't add resources\n");
 		goto out_dev_put;