On Mon, Jan 21, 2019 at 4:30 AM Kai-Heng Feng <kai.heng.f...@canonical.com> wrote: > > > > > On Jan 18, 2019, at 23:50, Benjamin Tissoires > > <benjamin.tissoi...@redhat.com> wrote: > > > > Hi Kai-Heng, > > > > On Mon, Jan 7, 2019 at 8:24 AM Kai-Heng Feng > > <kai.heng.f...@canonical.com> wrote: > >> > >> While using Elan touchpads, the message floods: > >> [ 136.138487] i2c_hid i2c-DELL08D6:00: i2c_hid_get_input: incomplete > >> report (14/65535) > >> > >> Though the message flood is annoying, the device it self works without > >> any issue. I suspect that the device in question takes too much time to > >> pull the IRQ back to high after I2C host has done reading its data. > >> > >> Since the host receives all useful data, let's ignore the input report > >> when there's no data. > >> > >> Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com> > > > > Thanks for the v3. > > > > This patch has just been brought to my attention, and I have one > > question before applying it: > > are those messages (without your patch) occurring all the time, or > > just after resume? > > All the time. > > The touchpad works fine though. The entire report is 0xff, so it can be > safely ignored.
Couple of things: - I have forgotten to tell you that I have applied this patch in for-5.1/i2c-hid, it will be pushed to linux-next today. - Dell told me that a BIOS fix was solving the issue. We can still quarry the patch, but there should not be a strong need for it when users upgrade their BIOS. Cheers, Benjamin > > > > > I wonder if the pm_suspend delay we talked about in the other thread > > would fix that issue in a cleaner way. > > I’ve replied in another thread, unfortunately it can’t. > > We can introduce msleep() between each commands though, but I don’t > think it’s good either. > > Kai-Heng > > > > > Cheers, > > Benjamin > > > >> --- > >> v3: > >> Fix compiler error/warnings. > >> > >> v2: > >> Use dev_warn_once() to warn the user about the situation. > >> > >> drivers/hid/i2c-hid/i2c-hid-core.c | 9 +++++++++ > >> 1 file changed, 9 insertions(+) > >> > >> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c > >> b/drivers/hid/i2c-hid/i2c-hid-core.c > >> index 8555ce7e737b..2f940c1de616 100644 > >> --- a/drivers/hid/i2c-hid/i2c-hid-core.c > >> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c > >> @@ -50,6 +50,7 @@ > >> #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1) > >> #define I2C_HID_QUIRK_NO_RUNTIME_PM BIT(2) > >> #define I2C_HID_QUIRK_DELAY_AFTER_SLEEP BIT(3) > >> +#define I2C_HID_QUIRK_BOGUS_IRQ BIT(4) > >> > >> /* flags */ > >> #define I2C_HID_STARTED 0 > >> @@ -179,6 +180,8 @@ static const struct i2c_hid_quirks { > >> I2C_HID_QUIRK_DELAY_AFTER_SLEEP }, > >> { USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001, > >> I2C_HID_QUIRK_NO_RUNTIME_PM }, > >> + { USB_VENDOR_ID_ELAN, HID_ANY_ID, > >> + I2C_HID_QUIRK_BOGUS_IRQ }, > >> { 0, 0 } > >> }; > >> > >> @@ -503,6 +506,12 @@ static void i2c_hid_get_input(struct i2c_hid *ihid) > >> return; > >> } > >> > >> + if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) { > >> + dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but " > >> + "there's no data\n", __func__); > >> + return; > >> + } > >> + > >> if ((ret_size > size) || (ret_size < 2)) { > >> dev_err(&ihid->client->dev, "%s: incomplete report > >> (%d/%d)\n", > >> __func__, size, ret_size); > >> -- > >> 2.17.1 > >> >