[PATCH 2/3] HID: logitech-hidpp: split g920_get_config()

From: Andrey Smirnov
Date: Mon Oct 07 2019 - 01:13:14 EST

Original version of g920_get_config() contained two kind of actions:

1. Device specific communication to query/set some parameters
which requires active communication channel with the device,
or, put in other way, for the call to be sandwiched between
hid_device_io_start() and hid_device_io_stop().

2. Input subsystem specific FF controller initialization which, in
order to access a valid 'struct hid_input' via
'hid->inputs.next', requires claimed hidinput which means be
executed after the call to hid_hw_start() with connect_mask
containing HID_CONNECT_HIDINPUT.

Location of g920_get_config() can only fulfill requirements for #1 and
not #2, which result in following backtrace:

[ 88.312258] logitech-hidpp-device 0003:046D:C262.0005: HID++ 4.2 device connected.
[ 88.320298] BUG: kernel NULL pointer dereference, address: 0000000000000018
[ 88.320304] #PF: supervisor read access in kernel mode
[ 88.320307] #PF: error_code(0x0000) - not-present page
[ 88.320309] PGD 0 P4D 0
[ 88.320315] Oops: 0000 [#1] SMP PTI
[ 88.320320] CPU: 1 PID: 3080 Comm: systemd-udevd Not tainted 5.4.0-rc1+ #31
[ 88.320322] Hardware name: Apple Inc. MacBookPro11,1/Mac-189A3D4F975D5FFC, BIOS 149.0.0.0.0 09/17/2018
[ 88.320334] RIP: 0010:hidpp_probe+0x61f/0x948 [hid_logitech_hidpp]
[ 88.320338] Code: 81 00 00 48 89 ef e8 f0 d6 ff ff 41 89 c6 85 c0 75 b5 0f b6 44 24 28 48 8b 5d 00 88 44 24 1e 89 44 24 0c 48 8b 83 18 1c 00 00 <48> 8b 48 18 48 8b 83 10 19 00 00 48 8b 40 40 48 89 0c 24 0f b7 80
[ 88.320341] RSP: 0018:ffffb0a6824aba68 EFLAGS: 00010246
[ 88.320345] RAX: 0000000000000000 RBX: ffff93a50756e000 RCX: 0000000000010408
[ 88.320347] RDX: 0000000000000000 RSI: ffff93a51f0ad0a0 RDI: 000000000002d0a0
[ 88.320350] RBP: ffff93a50416da28 R08: ffff93a50416da70 R09: ffff93a50416da70
[ 88.320352] R10: 000000148ae9e60c R11: 00000000000f1525 R12: ffff93a50756e000
[ 88.320354] R13: ffff93a50756f8d0 R14: 0000000000000000 R15: ffff93a50756fc38
[ 88.320358] FS: 00007f8d8c1e0940(0000) GS:ffff93a51f080000(0000) knlGS:0000000000000000
[ 88.320361] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 88.320363] CR2: 0000000000000018 CR3: 00000003996d8003 CR4: 00000000001606e0
[ 88.320366] Call Trace:
[ 88.320377] ? _cond_resched+0x15/0x30
[ 88.320387] ? create_pinctrl+0x2f/0x3c0
[ 88.320393] ? kernfs_link_sibling+0x94/0xe0
[ 88.320398] ? _cond_resched+0x15/0x30
[ 88.320402] ? kernfs_activate+0x5f/0x80
[ 88.320406] ? kernfs_add_one+0xe2/0x130
[ 88.320411] hid_device_probe+0x106/0x170
[ 88.320419] really_probe+0x147/0x3c0
[ 88.320424] driver_probe_device+0xb6/0x100
[ 88.320428] device_driver_attach+0x53/0x60
[ 88.320433] __driver_attach+0x8a/0x150
[ 88.320437] ? device_driver_attach+0x60/0x60
[ 88.320440] bus_for_each_dev+0x78/0xc0
[ 88.320445] bus_add_driver+0x14d/0x1f0
[ 88.320450] driver_register+0x6c/0xc0
[ 88.320453] ? 0xffffffffc0d67000
[ 88.320457] __hid_register_driver+0x4c/0x80
[ 88.320464] do_one_initcall+0x46/0x1f4
[ 88.320469] ? _cond_resched+0x15/0x30
[ 88.320474] ? kmem_cache_alloc_trace+0x162/0x220
[ 88.320481] ? do_init_module+0x23/0x230
[ 88.320486] do_init_module+0x5c/0x230
[ 88.320491] load_module+0x26e1/0x2990
[ 88.320502] ? ima_post_read_file+0xf0/0x100
[ 88.320508] ? __do_sys_finit_module+0xaa/0x110
[ 88.320512] __do_sys_finit_module+0xaa/0x110
[ 88.320520] do_syscall_64+0x5b/0x180
[ 88.320525] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 88.320528] RIP: 0033:0x7f8d8d1f01fd
[ 88.320532] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5b 8c 0c 00 f7 d8 64 89 01 48
[ 88.320535] RSP: 002b:00007ffefa3bb068 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 88.320539] RAX: ffffffffffffffda RBX: 000055922040cb40 RCX: 00007f8d8d1f01fd
[ 88.320541] RDX: 0000000000000000 RSI: 00007f8d8ce4984d RDI: 0000000000000006
[ 88.320543] RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
[ 88.320545] R10: 0000000000000006 R11: 0000000000000246 R12: 00007f8d8ce4984d
[ 88.320547] R13: 0000000000000000 R14: 000055922040efc0 R15: 000055922040cb40
[ 88.320551] Modules linked in: hid_logitech_hidpp(+) fuse rfcomm ccm xt_CHECKSUM xt_MASQUERADE bridge stp llc nf_nat_tftp nf_conntrack_tftp nf_conntrack_netbios_ns nf_conntrack_broadcast xt_CT ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat tun iptable_mangle iptable_raw iptable_security nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c ip_set nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables cmac bnep sunrpc dm_crypt nls_utf8 hfsplus intel_rapl_msr intel_rapl_common ath9k_htc ath9k_common x86_pkg_temp_thermal intel_powerclamp b43 ath9k_hw coretemp snd_hda_codec_hdmi cordic kvm_intel snd_hda_codec_cirrus mac80211 snd_hda_codec_generic ledtrig_audio kvm snd_hda_intel snd_intel_nhlt irqbypass snd_hda_codec btusb btrtl snd_hda_core ath btbcm ssb snd_hwdep btintel snd_seq crct10dif_pclmul iTCO_wdt snd_seq_device crc32_pclmul bluetooth mmc_core iTCO_vendor_support joydev cfg80211
[ 88.320602] applesmc ghash_clmulni_intel ecdh_generic snd_pcm input_polldev intel_cstate ecc intel_uncore thunderbolt snd_timer i2c_i801 libarc4 rfkill intel_rapl_perf lpc_ich mei_me pcspkr bcm5974 snd bcma mei soundcore acpi_als sbs kfifo_buf sbshc industrialio apple_bl i915 i2c_algo_bit drm_kms_helper drm uas crc32c_intel usb_storage video hid_apple
[ 88.320630] CR2: 0000000000000018
[ 88.320633] ---[ end trace 933491c8a4fadeb7 ]---
[ 88.320642] RIP: 0010:hidpp_probe+0x61f/0x948 [hid_logitech_hidpp]
[ 88.320645] Code: 81 00 00 48 89 ef e8 f0 d6 ff ff 41 89 c6 85 c0 75 b5 0f b6 44 24 28 48 8b 5d 00 88 44 24 1e 89 44 24 0c 48 8b 83 18 1c 00 00 <48> 8b 48 18 48 8b 83 10 19 00 00 48 8b 40 40 48 89 0c 24 0f b7 80
[ 88.320647] RSP: 0018:ffffb0a6824aba68 EFLAGS: 00010246
[ 88.320650] RAX: 0000000000000000 RBX: ffff93a50756e000 RCX: 0000000000010408
[ 88.320652] RDX: 0000000000000000 RSI: ffff93a51f0ad0a0 RDI: 000000000002d0a0
[ 88.320655] RBP: ffff93a50416da28 R08: ffff93a50416da70 R09: ffff93a50416da70
[ 88.320657] R10: 000000148ae9e60c R11: 00000000000f1525 R12: ffff93a50756e000
[ 88.320659] R13: ffff93a50756f8d0 R14: 0000000000000000 R15: ffff93a50756fc38
[ 88.320662] FS: 00007f8d8c1e0940(0000) GS:ffff93a51f080000(0000) knlGS:0000000000000000
[ 88.320664] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 88.320667] CR2: 0000000000000018 CR3: 00000003996d8003 CR4: 00000000001606e0

To solve this issue:

1. Split g920_get_config() such that all of the device specific
communication remains a part of the function and input subsystem
initialization bits go to hidpp_ff_init()

2. Move call to hidpp_ff_init() from being a part of
g920_get_config() to be the last step of .probe(), right after a
call to hid_hw_start() with connect_mask containing
HID_CONNECT_HIDINPUT.

Fixes: 91cf9a98ae41 ("HID: logitech-hidpp: make .probe usbhid capable")
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Cc: Jiri Kosina <jikos@xxxxxxxxxx>
Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Cc: Henrik Rydberg <rydberg@xxxxxxxxxxx>
Cc: Sam Bazely <sambazley@xxxxxxxxxxxx>
Cc: Pierre-Loup A. Griffais <pgriffais@xxxxxxxxxxxxxxxxx>
Cc: Austin Palmer <austinp@xxxxxxxxxxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/hid/hid-logitech-hidpp.c | 134 ++++++++++++++++++++-----------
1 file changed, 85 insertions(+), 49 deletions(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 58eb928224e5..cadf36d6c6f3 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -1669,6 +1669,7 @@ static void hidpp_touchpad_raw_xy_event(struct hidpp_device *hidpp_dev,

#define HIDPP_FF_EFFECTID_NONE -1
#define HIDPP_FF_EFFECTID_AUTOCENTER -2
+#define HIDPP_AUTOCENTER_PARAMS_LENGTH 18

#define HIDPP_FF_MAX_PARAMS 20
#define HIDPP_FF_RESERVED_SLOTS 1
@@ -2009,7 +2010,7 @@ static int hidpp_ff_erase_effect(struct input_dev *dev, int effect_id)
static void hidpp_ff_set_autocenter(struct input_dev *dev, u16 magnitude)
{
struct hidpp_ff_private_data *data = dev->ff->private;
- u8 params[18];
+ u8 params[HIDPP_AUTOCENTER_PARAMS_LENGTH];

dbg_hid("Setting autocenter to %d.\n", magnitude);

@@ -2086,7 +2087,7 @@ static void hidpp_ff_destroy(struct ff_device *ff)
ff->private = NULL;
}

-static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
+static int hidpp_ff_init(struct hidpp_device *hidpp)
{
struct hid_device *hid = hidpp->hid_dev;
struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
@@ -2094,9 +2095,8 @@ static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
const struct usb_device_descriptor *udesc = &(hid_to_usb_dev(hid)->descriptor);
const u16 bcdDevice = le16_to_cpu(udesc->bcdDevice);
struct ff_device *ff;
- struct hidpp_report response;
struct hidpp_ff_private_data *data = hidpp->private_data;
- int error, j, num_slots;
+ int error, j, num_slots = data->num_effects;
u8 version;

if (!dev) {
@@ -2114,19 +2114,6 @@ static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
for (j = 0; hidpp_ff_effects_v2[j] >= 0; j++)
set_bit(hidpp_ff_effects_v2[j], dev->ffbit);

- /* Read number of slots available in device */
- error = hidpp_send_fap_command_sync(hidpp, feature_index,
- HIDPP_FF_GET_INFO, NULL, 0, &response);
- if (error) {
- if (error < 0)
- return error;
- hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
- __func__, error);
- return -EPROTO;
- }
-
- num_slots = response.fap.params[0] - HIDPP_FF_RESERVED_SLOTS;
-
error = input_ff_create(dev, num_slots);

if (error) {
@@ -2145,10 +2132,7 @@ static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
}

data->hidpp = hidpp;
- data->feature_index = feature_index;
data->version = version;
- data->slot_autocenter = 0;
- data->num_effects = num_slots;
for (j = 0; j < num_slots; j++)
data->effect_ids[j] = -1;

@@ -2162,37 +2146,14 @@ static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
ff->set_autocenter = hidpp_ff_set_autocenter;
ff->destroy = hidpp_ff_destroy;

-
- /* reset all forces */
- error = hidpp_send_fap_command_sync(hidpp, feature_index,
- HIDPP_FF_RESET_ALL, NULL, 0, &response);
-
- /* Read current Range */
- error = hidpp_send_fap_command_sync(hidpp, feature_index,
- HIDPP_FF_GET_APERTURE, NULL, 0, &response);
- if (error)
- hid_warn(hidpp->hid_dev, "Failed to read range from device!\n");
- data->range = error ? 900 : get_unaligned_be16(&response.fap.params[0]);
-
/* Create sysfs interface */
error = device_create_file(&(hidpp->hid_dev->dev), &dev_attr_range);
if (error)
hid_warn(hidpp->hid_dev, "Unable to create sysfs interface for \"range\", errno %d!\n", error);

- /* Read the current gain values */
- error = hidpp_send_fap_command_sync(hidpp, feature_index,
- HIDPP_FF_GET_GLOBAL_GAINS, NULL, 0, &response);
- if (error)
- hid_warn(hidpp->hid_dev, "Failed to read gain values from device!\n");
- data->gain = error ? 0xffff : get_unaligned_be16(&response.fap.params[0]);
- /* ignore boost value at response.fap.params[2] */
-
/* init the hardware command queue */
atomic_set(&data->workqueue_size, 0);

- /* initialize with zero autocenter to get wheel in usable state */
- hidpp_ff_set_autocenter(dev, 0);
-
hid_info(hid, "Force feedback support loaded (firmware release %d).\n",
version);

@@ -2712,6 +2673,30 @@ static int k400_connect(struct hid_device *hdev, bool connected)

#define HIDPP_PAGE_G920_FORCE_FEEDBACK 0x8123

+static int g920_ff_set_autocenter(struct hidpp_device *hidpp)
+{
+ struct hidpp_report response;
+ struct hidpp_ff_private_data *data = hidpp->private_data;
+ u8 params[HIDPP_AUTOCENTER_PARAMS_LENGTH] = {
+ [1] = HIDPP_FF_EFFECT_SPRING | HIDPP_FF_EFFECT_AUTOSTART,
+ };
+ int ret;
+
+ /* initialize with zero autocenter to get wheel in usable state */
+
+ dbg_hid("Setting autocenter to 0.\n");
+ ret = hidpp_send_fap_command_sync(hidpp, data->feature_index,
+ HIDPP_FF_DOWNLOAD_EFFECT,
+ params, ARRAY_SIZE(params),
+ &response);
+ if (ret)
+ hid_warn(hidpp->hid_dev, "Failed to autocenter device!\n");
+ else
+ data->slot_autocenter = response.fap.params[0];
+
+ return ret;
+}
+
static int g920_allocate(struct hid_device *hdev)
{
struct hidpp_device *hidpp = hid_get_drvdata(hdev);
@@ -2728,22 +2713,65 @@ static int g920_allocate(struct hid_device *hdev)

static int g920_get_config(struct hidpp_device *hidpp)
{
+ struct hidpp_ff_private_data *data = hidpp->private_data;
+ struct hidpp_report response;
u8 feature_type;
- u8 feature_index;
int ret;

/* Find feature and store for later use */
ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_G920_FORCE_FEEDBACK,
- &feature_index, &feature_type);
+ &data->feature_index, &feature_type);
if (ret)
return ret;

- ret = hidpp_ff_init(hidpp, feature_index);
+ /* Read number of slots available in device */
+ ret = hidpp_send_fap_command_sync(hidpp, data->feature_index,
+ HIDPP_FF_GET_INFO,
+ NULL, 0,
+ &response);
+ if (ret) {
+ if (ret < 0)
+ return ret;
+ hid_err(hidpp->hid_dev,
+ "%s: received protocol error 0x%02x\n", __func__, ret);
+ return -EPROTO;
+ }
+
+ data->num_effects = response.fap.params[0] - HIDPP_FF_RESERVED_SLOTS;
+
+ /* reset all forces */
+ ret = hidpp_send_fap_command_sync(hidpp, data->feature_index,
+ HIDPP_FF_RESET_ALL,
+ NULL, 0,
+ &response);
if (ret)
- hid_warn(hidpp->hid_dev, "Unable to initialize force feedback support, errno %d\n",
- ret);
+ hid_warn(hidpp->hid_dev, "Failed to reset all forces!\n");

- return 0;
+ ret = hidpp_send_fap_command_sync(hidpp, data->feature_index,
+ HIDPP_FF_GET_APERTURE,
+ NULL, 0,
+ &response);
+ if (ret) {
+ hid_warn(hidpp->hid_dev,
+ "Failed to read range from device!\n");
+ }
+ data->range = ret ?
+ 900 : get_unaligned_be16(&response.fap.params[0]);
+
+ /* Read the current gain values */
+ ret = hidpp_send_fap_command_sync(hidpp, data->feature_index,
+ HIDPP_FF_GET_GLOBAL_GAINS,
+ NULL, 0,
+ &response);
+ if (ret)
+ hid_warn(hidpp->hid_dev,
+ "Failed to read gain values from device!\n");
+ data->gain = ret ?
+ 0xffff : get_unaligned_be16(&response.fap.params[0]);
+
+ /* ignore boost value at response.fap.params[2] */
+
+ return g920_ff_set_autocenter(hidpp);
}

/* -------------------------------------------------------------------------- */
@@ -3641,6 +3669,14 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
goto hid_hw_start_fail;
}

+ if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
+ ret = hidpp_ff_init(hidpp);
+ if (ret)
+ hid_warn(hidpp->hid_dev,
+ "Unable to initialize force feedback support, errno %d\n",
+ ret);
+ }
+
return ret;

hid_hw_init_fail:
--
2.21.0