From: Dmitry Torokhov dmitry.torokhov@gmail.com
commit 3fe6acd4dc922237b30e55473c9349c6ce0690f3 upstream.
Unfortunately details of USB HID transport bled into HID core and handling of numbered/unnumbered reports is quite a mess, with hid_report_len() calculating the length according to USB rules, and hid_hw_raw_request() adding report ID to the buffer for both numbered and unnumbered reports.
Untangling it all requres a lot of changes in HID, so for now let's handle this in the driver.
[jkosina@suse.cz: microoptimize field->report->id to report->id] Fixes: 14c9c014babe ("HID: add vivaldi HID driver") Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Tested-by: Stephen Boyd swboyd@chromium.org # CoachZ Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hid/hid-vivaldi.c | 34 ++++++++++++++++++++++++++++------ 1 file changed, 28 insertions(+), 6 deletions(-)
--- a/drivers/hid/hid-vivaldi.c +++ b/drivers/hid/hid-vivaldi.c @@ -74,10 +74,11 @@ static void vivaldi_feature_mapping(stru struct hid_usage *usage) { struct vivaldi_data *drvdata = hid_get_drvdata(hdev); + struct hid_report *report = field->report; int fn_key; int ret; u32 report_len; - u8 *buf; + u8 *report_data, *buf;
if (field->logical != HID_USAGE_FN_ROW_PHYSMAP || (usage->hid & HID_USAGE_PAGE) != HID_UP_ORDINAL) @@ -89,12 +90,24 @@ static void vivaldi_feature_mapping(stru if (fn_key > drvdata->max_function_row_key) drvdata->max_function_row_key = fn_key;
- buf = hid_alloc_report_buf(field->report, GFP_KERNEL); - if (!buf) + report_data = buf = hid_alloc_report_buf(report, GFP_KERNEL); + if (!report_data) return;
- report_len = hid_report_len(field->report); - ret = hid_hw_raw_request(hdev, field->report->id, buf, + report_len = hid_report_len(report); + if (!report->id) { + /* + * hid_hw_raw_request() will stuff report ID (which will be 0) + * into the first byte of the buffer even for unnumbered + * reports, so we need to account for this to avoid getting + * -EOVERFLOW in return. + * Note that hid_alloc_report_buf() adds 7 bytes to the size + * so we can safely say that we have space for an extra byte. + */ + report_len++; + } + + ret = hid_hw_raw_request(hdev, report->id, report_data, report_len, HID_FEATURE_REPORT, HID_REQ_GET_REPORT); if (ret < 0) { @@ -103,7 +116,16 @@ static void vivaldi_feature_mapping(stru goto out; }
- ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf, + if (!report->id) { + /* + * Undo the damage from hid_hw_raw_request() for unnumbered + * reports. + */ + report_data++; + report_len--; + } + + ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, report_data, report_len, 0); if (ret) { dev_warn(&hdev->dev, "failed to report feature %d\n",