[PATCH v2 8/8] mfd: cros_ec: add a dev_release empty method.

From: Enric Balletbo i Serra
Date: Mon Nov 26 2018 - 12:52:16 EST


Devices are required to provide a release method. This patch fixes the
following WARN():

[ 47.218707] ------------[ cut here ]------------
[ 47.223901] Device 'cros_ec' does not have a release() function, it is broken and must be fixed.
[ 47.234430] WARNING: CPU: 0 PID: 3585 at drivers/base/core.c:895 device_release+0x80/0x90
[ 47.243560] Modules linked in: btusb btrtl btintel btbcm bluetooth ecdh_generic [...]
[ 47.323851] CPU: 0 PID: 3585 Comm: rmmod Not tainted 4.20.0-rc2+ #29
[ 47.330947] Hardware name: Google Kevin (DT)
[ 47.335714] pstate: 40000005 (nZcv daif -PAN -UAO)
[ 47.341063] pc : device_release+0x80/0x90
[ 47.345537] lr : device_release+0x80/0x90
[ 47.350001] sp : ffff00000b17bc70
[ 47.353698] x29: ffff00000b17bc70 x28: ffff8000e48e9a80
[ 47.359629] x27: 0000000000000000 x26: 0000000000000000
[ 47.365561] x25: 0000000056000000 x24: 0000000000000015
[ 47.371492] x23: ffff8000f0248060 x22: ffff000000b700a0
[ 47.377414] x21: ffff8000edf56100 x20: ffff8000edd13028
[ 47.383346] x19: ffff8000edd13018 x18: 0000000000000095
[ 47.389278] x17: 0000000000000000 x16: 0000000000000000
[ 47.395209] x15: 0000000000000400 x14: 0000000000000400
[ 47.401131] x13: 00000000000001a7 x12: 0000000000000000
[ 47.407053] x11: 0000000000000001 x10: 0000000000000960
[ 47.412976] x9 : ffff00000b17b9b0 x8 : ffff8000e48ea440
[ 47.418898] x7 : ffff8000ee9090c0 x6 : ffff8000f7d0b0b8
[ 47.424830] x5 : ffff8000f7d0b0b8 x4 : 0000000000000000
[ 47.430752] x3 : ffff8000f7d11e68 x2 : ffff8000e48e9a80
[ 47.436674] x1 : 37d859939c964800 x0 : 0000000000000000
[ 47.442597] Call trace:
[ 47.445324] device_release+0x80/0x90
[ 47.449414] kobject_put+0x74/0xe8
[ 47.453210] device_unregister+0x20/0x30
[ 47.457592] ec_device_remove+0x34/0x48 [cros_ec_dev]
[ 47.463233] platform_drv_remove+0x28/0x48
[ 47.467805] device_release_driver_internal+0x1a8/0x240
[ 47.473630] driver_detach+0x40/0x80
[ 47.477609] bus_remove_driver+0x54/0xa8
[ 47.481986] driver_unregister+0x2c/0x58
[ 47.486355] platform_driver_unregister+0x10/0x18
[ 47.491599] cros_ec_dev_exit+0x1c/0x258 [cros_ec_dev]
[ 47.497338] __arm64_sys_delete_module+0x16c/0x1f8
[ 47.502689] el0_svc_common+0x84/0xd8
[ 47.506776] el0_svc_handler+0x2c/0x80
[ 47.510960] el0_svc+0x8/0xc
[ 47.514171] ---[ end trace 9087279fc8c03450 ]---

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---

Changes in v2:
- Fix WARN when unloading. This is new in these series.

drivers/mfd/cros_ec_dev.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 13b6dc26dc9a..bd561e91153a 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -35,9 +35,14 @@
#define CROS_MAX_DEV 128
static int ec_major;

+static void cros_ec_dev_release(struct device *dev)
+{
+}
+
static struct class cros_class = {
.owner = THIS_MODULE,
.name = "chromeos",
+ .dev_release = cros_ec_dev_release,
};

/* Basic communication */
--
2.19.1