Messages in this thread | | | Date | Thu, 18 Aug 2022 16:33:53 +0300 | Subject | Re: [PATCH] HID: i2c-hid: fix the report-id passed in via set_or_send_report | From | Tero Kristo <> |
| |
Hello,
Yes, I think this is a problem. Maybe we need to introduce some sort of quirk for the devices that are broken and expect the 0xf device id to be passed to them?
-Tero
On 18/08/2022 13:27, Angela Czubak wrote: > Hi Tero, > > I believe this is not the right solution. To my mind the spec does not > mention anything that the ID in the payload of SET_REPORT command > should be altered; you have a full byte to us, so why not? > Other than that this will result into problems with sending reports > via output register: for any report with report ID >=0xF we will get > the same report ID in the payload, so how could the device know which > one we have in mind? > Dmitry's rework was intended to actually solve problems with large > report IDs being incorrectly overwritten with 0xF. > > Regards, > Angela > > On Tue, Jul 26, 2022 at 10:05 AM Tero Kristo > <tero.kristo@linux.intel.com> wrote: >> The formatting of the data passed to the i2c HID data register was >> changed with the re-work of the i2c-hid-core. Previously the report ID >> passed in was encoded as 0xF if the report-id was greater than 0xF >> (similar to what is done with the command portion.) Now with the rework, >> a full report-id is passed in always, and this causes the messages to be >> rejected by the i2c controller. Fix this by encoding the report-id >> field in the same manner as previously was done. >> >> Fixes: dbe0dd5fd2e0 ("HID: i2c-hid: explicitly code setting and sending >> reports") >> Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com> >> --- >> drivers/hid/i2c-hid/i2c-hid-core.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c >> index c078f09a2318..156b12f840c4 100644 >> --- a/drivers/hid/i2c-hid/i2c-hid-core.c >> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c >> @@ -296,6 +296,9 @@ static size_t i2c_hid_format_report(u8 *buf, int report_id, >> { >> size_t length = sizeof(__le16); /* reserve space to store size */ >> >> + if (report_id > 0xF) >> + report_id = 0xF; >> + >> if (report_id) >> buf[length++] = report_id; >> >> -- >> 2.25.1 >>
| |