linux-kernel - Re: [PATCH v2 16/20] extcon: intel-cht-wc: Use new intel_cht_wc_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <380053ee-4a4a-963c-4f70-6b9dcfef1b98@redhat.com>
Date:   Wed, 17 Nov 2021 23:28:32 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Chanwoo Choi <cwchoi00@...il.com>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Mark Gross <markgross@...nel.org>,
        Andy Shevchenko <andy@...radead.org>,
        Wolfram Sang <wsa@...-dreams.de>,
        Sebastian Reichel <sre@...nel.org>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Ard Biesheuvel <ardb@...nel.org>
Cc:     Len Brown <lenb@...nel.org>, linux-acpi@...r.kernel.org,
        Yauhen Kharuzhy <jekhor@...il.com>,
        Tsuchiya Yuto <kitakar@...il.com>,
        platform-driver-x86@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-efi@...r.kernel.org
Subject: Re: [PATCH v2 16/20] extcon: intel-cht-wc: Use new
 intel_cht_wc_get_model() helper

Hi,

On 11/17/21 07:47, Chanwoo Choi wrote:
> On 21. 11. 15. 오전 2:03, Hans de Goede wrote:
>> The CHT_WC_VBUS_GPIO_CTLO GPIO actually driving an external 5V Vboost
>> converter for Vbus depends on the board on which the Cherry Trail -
>> Whiskey Cove PMIC is actually used.
>>
>> Since the information about the exact PMIC setup is necessary in other
>> places too, the drivers/mfd/intel_soc_pmic_chtwc.c code now has a new
>> intel_cht_wc_get_model() helper.
>>
>> Only poke the CHT_WC_VBUS_GPIO_CTLO GPIO if this new helper returns
>> INTEL_CHT_WC_GPD_WIN_POCKET, which indicates the Type-C (with PD and
>> DP-altmode) setup used on the GPD pocket and GPD win; and on which
>> this GPIO actually controls an external 5V Vboost converter.
>>
>> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
>> ---
>>   drivers/extcon/extcon-intel-cht-wc.c | 35 +++++++++++++++++-----------
>>   1 file changed, 21 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/extcon/extcon-intel-cht-wc.c b/drivers/extcon/extcon-intel-cht-wc.c
>> index 771f6f4cf92e..a5aeeecc44fb 100644
>> --- a/drivers/extcon/extcon-intel-cht-wc.c
>> +++ b/drivers/extcon/extcon-intel-cht-wc.c
>> @@ -14,6 +14,7 @@
>>   #include <linux/module.h>
>>   #include <linux/mod_devicetable.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/property.h>
>>   #include <linux/regmap.h>
>>   #include <linux/slab.h>
>>   @@ -358,20 +359,26 @@ static int cht_wc_extcon_probe(struct platform_device *pdev)
>>       if (IS_ERR(ext->edev))
>>           return PTR_ERR(ext->edev);
>>   -    /*
>> -     * When a host-cable is detected the BIOS enables an external 5v boost
>> -     * converter to power connected devices there are 2 problems with this:
>> -     * 1) This gets seen by the external battery charger as a valid Vbus
>> -     *    supply and it then tries to feed Vsys from this creating a
>> -     *    feedback loop which causes aprox. 300 mA extra battery drain
>> -     *    (and unless we drive the external-charger-disable pin high it
>> -     *    also tries to charge the battery causing even more feedback).
>> -     * 2) This gets seen by the pwrsrc block as a SDP USB Vbus supply
>> -     * Since the external battery charger has its own 5v boost converter
>> -     * which does not have these issues, we simply turn the separate
>> -     * external 5v boost converter off and leave it off entirely.
>> -     */
>> -    cht_wc_extcon_set_5v_boost(ext, false);
>> +    switch (intel_cht_wc_get_model()) {
> 
> intel_cht_wc_get_model() is defined in driver/mfd/intel_soc_pmic_chtwc.c
> 
> Usually, mfd drivers share the data structure such as struct intel_soc_pmic. But, didn't call the exported function for only
> specific driver between linux kernel framework (extcon vs. mfd).
> 
> So that I think that you better to update the mode information
> to 'struct intel_soc_pmic' data structure and then use it
> instead of using the exported function which may make the confusion.

That is a good idea, thanks.

I've implemented this suggestion for the upcoming v3 of the patch-set.

Regards,

Hans


> 
>> +    case INTEL_CHT_WC_GPD_WIN_POCKET:
>> +        /*
>> +         * When a host-cable is detected the BIOS enables an external 5v boost
>> +         * converter to power connected devices there are 2 problems with this:
>> +         * 1) This gets seen by the external battery charger as a valid Vbus
>> +         *    supply and it then tries to feed Vsys from this creating a
>> +         *    feedback loop which causes aprox. 300 mA extra battery drain
>> +         *    (and unless we drive the external-charger-disable pin high it
>> +         *    also tries to charge the battery causing even more feedback).
>> +         * 2) This gets seen by the pwrsrc block as a SDP USB Vbus supply
>> +         * Since the external battery charger has its own 5v boost converter
>> +         * which does not have these issues, we simply turn the separate
>> +         * external 5v boost converter off and leave it off entirely.
>> +         */
>> +        cht_wc_extcon_set_5v_boost(ext, false);
>> +        break;
>> +    default:
>> +        break;
>> +    }
>>         /* Enable sw control */
>>       ret = cht_wc_extcon_sw_control(ext, true);
>>
> 
>