On Tuesday 16 December 2014 09:33:44 Benjamin Tissoires wrote: > On Mon, Dec 15, 2014 at 7:50 PM, Peter Wu <pe...@lekensteyn.nl> wrote: > > Devices speaking HID++ 2.0 report a different error code (0xff). Detect > > these errors too to avoid 5 second delays when the device reports an > > error. Caught by... well, a bug in the QEMU emulation of this receiver. > > > > Renamed fap to rap for HID++ 1.0 errors because it is more logical, > > it has no functional difference. > > > > Signed-off-by: Peter Wu <pe...@lekensteyn.nl> > > --- > > I'd like to have Nestor's opinion on this. I did not manage to find on > the documentation that HID++ 2.0 Long report error code is 0xff, so > introducing this change without Logitech's blessing would be > unfortunate. > I understand this will fix your qemu problem, but I am not entirely > sure if we do not have to check on 0xff and 0x8f in both short and > long responses. > > Cheers, > Benjamin
The error code was found by probing the hardware. The HID++ 2.0 spec does define some error codes, for example an OutOfRange error when GetFeatureID is called with a featureIndex greater than the available features count. The documentation also defines the valid FeatureIndex range as 1..254, so I thought it was reasonable to assume that 0xff is the HID++ 2.0 error indicator. Nestor, so far I have only seen the OutOfRange error when the arguments are invalid. Are there other cases where HID++ 2.0 are reported instead of HID++ 1.0? QEMU was not the problem though, it was just a bug in my usb-ltunify-receiver device emulation which exposed this missing check. Kind regards, Peter > > drivers/hid/hid-logitech-hidpp.c | 17 ++++++++++++++--- > > 1 file changed, 14 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/hid/hid-logitech-hidpp.c > > b/drivers/hid/hid-logitech-hidpp.c > > index 2f420c0..ae23dec 100644 > > --- a/drivers/hid/hid-logitech-hidpp.c > > +++ b/drivers/hid/hid-logitech-hidpp.c > > @@ -105,6 +105,7 @@ struct hidpp_device { > > }; > > > > > > +/* HID++ 1.0 error codes */ > > #define HIDPP_ERROR 0x8f > > #define HIDPP_ERROR_SUCCESS 0x00 > > #define HIDPP_ERROR_INVALID_SUBID 0x01 > > @@ -119,6 +120,8 @@ struct hidpp_device { > > #define HIDPP_ERROR_REQUEST_UNAVAILABLE 0x0a > > #define HIDPP_ERROR_INVALID_PARAM_VALUE 0x0b > > #define HIDPP_ERROR_WRONG_PIN_CODE 0x0c > > +/* HID++ 2.0 error codes */ > > +#define HIDPP20_ERROR 0xff > > > > static void hidpp_connect_event(struct hidpp_device *hidpp_dev); > > > > @@ -192,9 +195,16 @@ static int hidpp_send_message_sync(struct hidpp_device > > *hidpp, > > } > > > > if (response->report_id == REPORT_ID_HIDPP_SHORT && > > - response->fap.feature_index == HIDPP_ERROR) { > > + response->rap.sub_id == HIDPP_ERROR) { > > + ret = response->rap.params[1]; > > + dbg_hid("%s:got hidpp error %02X\n", __func__, ret); > > + goto exit; > > + } > > + > > + if (response->report_id == REPORT_ID_HIDPP_LONG && > > + response->fap.feature_index == HIDPP20_ERROR) { > > ret = response->fap.params[1]; > > - dbg_hid("__hidpp_send_report got hidpp error %02X\n", ret); > > + dbg_hid("%s:got hidpp 2.0 error %02X\n", __func__, ret); > > goto exit; > > } > > > > @@ -271,7 +281,8 @@ static inline bool hidpp_match_answer(struct > > hidpp_report *question, > > static inline bool hidpp_match_error(struct hidpp_report *question, > > struct hidpp_report *answer) > > { > > - return (answer->fap.feature_index == HIDPP_ERROR) && > > + return ((answer->rap.sub_id == HIDPP_ERROR) || > > + (answer->fap.feature_index == HIDPP20_ERROR)) && > > (answer->fap.funcindex_clientid == question->fap.feature_index) > > && > > (answer->fap.params[0] == question->fap.funcindex_clientid); > > } > > -- > > 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html