diff options
Diffstat (limited to 'drivers/hid/i2c-hid/i2c-hid.c')
| -rw-r--r-- | drivers/hid/i2c-hid/i2c-hid.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index b1bce80..865e7c2 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -427,6 +427,15 @@ static int i2c_hid_hwreset(struct i2c_client *client) if (ret) goto out_unlock; + /* + * The HID over I2C specification states that if a DEVICE needs time + * after the PWR_ON request, it should utilise CLOCK stretching. + * However, it has been observered that the Windows driver provides a + * 1ms sleep between the PWR_ON and RESET requests and that some devices + * rely on this. + */ + usleep_range(1000, 5000); + i2c_hid_dbg(ihid, "resetting...\n"); ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0); @@ -595,7 +604,8 @@ static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) { /* the worst case is computed from the set_report command with a * reportID > 15 and the maximum report length */ - int args_len = sizeof(__u8) + /* optional ReportID byte */ + int args_len = sizeof(__u8) + /* ReportID */ + sizeof(__u8) + /* optional ReportID byte */ sizeof(__u16) + /* data register */ sizeof(__u16) + /* size of the report */ report_size; /* report */ |