[PATCH 1/1] UBUNTU: SAUCE: i2c: designware: Add disable runtime pm quirk

[Kai-Heng Feng]

at 10:38, AceLan Kao <acelan.kao at canonical.com> wrote:

> BugLink: https://bugs.launchpad.net/bugs/1833484
>
> Dell machines come with goodix touchpad IC suffer from the double click
> issue if the Designware I2C adapter enters runtime suspend.
>
> It's because the goodix re-assert the interrupt if host doesn't read the
> data within 100ms and desiginware takes a longer time to wake up from
> runtime suspend. In the case, it got a second interrupt during
> resuming, so it thinks it's a double click.
>
> There is no simple way to fix this, it's a firmware issue and goodix
> agrees to fix this in their firmware on next release, but this issue is
> still affects the machines that don't come with an updated firmware. So,
> add a quirk to mark those machines and avoid the designware to enter
> runtime suspend.
>
> Signed-off-by: AceLan Kao <acelan.kao at canonical.com>
> ---
>  drivers/i2c/busses/i2c-designware-master.c | 30 ++++++++++++++++++++--
>  1 file changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-designware-master.c  
> b/drivers/i2c/busses/i2c-designware-master.c
> index bb8e3f149979..7acb015f0470 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -9,6 +9,7 @@
>   * Copyright (C) 2009 Provigent Ltd.
>   */
>  #include <linux/delay.h>
> +#include <linux/dmi.h>
>  #include <linux/err.h>
>  #include <linux/errno.h>
>  #include <linux/export.h>
> @@ -22,6 +23,25 @@
>
>  #include "i2c-designware-core.h"
>
> +static int no_runtime_pm;
> +static const struct dmi_system_id i2c_dw_no_runtime_pm[] = {
> +	{
> +		.ident = "Dell Vostro 5390",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 5390"),
> +		},
> +	},
> +	{
> +		.ident = "Dell Vostro 5391",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 5391"),
> +		},
> +	},
> +	{ }
> +};
> +
>  static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
>  {
>  	/* Configure Tx/Rx FIFO threshold levels */
> @@ -424,7 +444,8 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg  
> msgs[], int num)
>
>  	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
>
> -	pm_runtime_get_sync(dev->dev);
> +	if (!no_runtime_pm)
> +		pm_runtime_get_sync(dev->dev);
>
>  	if (dev->suspended) {
>  		dev_err(dev->dev, "Error %s call while suspended\n", __func__);
> @@ -502,7 +523,8 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg  
> msgs[], int num)
>
>  done_nolock:
>  	pm_runtime_mark_last_busy(dev->dev);
> -	pm_runtime_put_autosuspend(dev->dev);
> +	if (!no_runtime_pm)
> +		pm_runtime_put_autosuspend(dev->dev);
>
>  	return ret;
>  }
> @@ -734,6 +756,10 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
>  	if (ret)
>  		return ret;
>
> +	no_runtime_pm = dmi_check_system(i2c_dw_no_runtime_pm);
> +	if (no_runtime_pm)
> +		__pm_runtime_disable(dev->dev, true);
> +

I think using pm helpers in i2c_dw_xfer() is unnecessary if we do this in  
i2c_dw_probe():

--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -743,7 +743,9 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
         ret = i2c_add_numbered_adapter(adap);
         if (ret)
                 dev_err(dev->dev, "failure adding adapter: %d\n", ret);
-       pm_runtime_put_noidle(dev->dev);
+
+       if (!no_runtime_pm)
+               pm_runtime_put_noidle(dev->dev);

         return ret;
  }


>  	/*
>  	 * Increment PM usage count during adapter registration in order to
>  	 * avoid possible spurious runtime suspend when adapter device is
> -- 
> 2.17.1
>
>
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