> On Jan 29, 2019, at 18:05, Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> wrote: > > On Mon, Jan 21, 2019 at 4:30 AM Kai-Heng Feng > <kai.heng.feng@xxxxxxxxxxxxx> wrote: >> >> >> >>> On Jan 18, 2019, at 23:50, Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> wrote: >>> >>> Hi Kai-Heng, >>> >>> On Mon, Jan 7, 2019 at 8:24 AM Kai-Heng Feng >>> <kai.heng.feng@xxxxxxxxxxxxx> 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.feng@xxxxxxxxxxxxx> >>> >>> 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. Thanks! > - 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. Multiple platforms are affected by this issue [1], so the patch can still be really helpful. [1] https://bugs.launchpad.net/bugs/1784152 Kai-Heng > > 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
