From 7e3cc447ff8906558619b1ecc46e4bd776a4f3a6 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 6 Feb 2013 12:10:47 +0100 Subject: HID: multitouch: do not use pointers towards hid-core The previous implementation registered a pointer towards hid-core to the value of contact count. This is not safe and may be difficult to debug if hid-core ever changes its implementation. The use of regular indexes is a better choice. Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/hid-multitouch.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 28af54fb07d..e22fbd33ad8 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -84,7 +84,8 @@ struct mt_device { struct mt_class mtclass; /* our mt device class */ struct mt_fields *fields; /* temporary placeholder for storing the multitouch fields */ - __s32 *contactcount; /* contact count value in the report */ + int cc_index; /* contact count field index in the report */ + int cc_value_index; /* contact count value index in the field */ unsigned last_field_index; /* last field index of the report */ unsigned last_slot_field; /* the last field of a slot */ unsigned mt_report_id; /* the report ID of the multitouch device */ @@ -269,7 +270,7 @@ static ssize_t mt_set_quirks(struct device *dev, td->mtclass.quirks = val; - if (!td->contactcount) + if (td->cc_index < 0) td->mtclass.quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE; return count; @@ -483,7 +484,8 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, td->last_field_index = field->index; return 1; case HID_DG_CONTACTCOUNT: - td->contactcount = field->value + usage->usage_index; + td->cc_index = field->index; + td->cc_value_index = usage->usage_index; td->last_field_index = field->index; return 1; case HID_DG_CONTACTMAX: @@ -701,8 +703,12 @@ static void mt_report(struct hid_device *hid, struct hid_report *report) * Includes multi-packet support where subsequent * packets are sent with zero contactcount. */ - if (td->contactcount && *td->contactcount) - td->num_expected = *td->contactcount; + if (td->cc_index >= 0) { + struct hid_field *field = report->field[td->cc_index]; + int value = field->value[td->cc_value_index]; + if (value) + td->num_expected = value; + } for (r = 0; r < report->maxfield; r++) { field = report->field[r]; @@ -786,7 +792,7 @@ static void mt_post_parse(struct mt_device *td) td->last_slot_field = f->usages[field_count_per_touch - 1]; } - if (!td->contactcount) + if (td->cc_index < 0) cls->quirks &= ~MT_QUIRK_CONTACT_CNT_ACCURATE; } @@ -845,6 +851,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id) td->mtclass = *mtclass; td->inputmode = -1; td->maxcontact_report_id = -1; + td->cc_index = -1; hid_set_drvdata(hdev, td); td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL); -- cgit v1.2.3