From: Hans de Goede <hdegoede@redhat.com> To: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Coiby Xu <coiby.xu@gmail.com>, Linus Walleij <linus.walleij@linaro.org>, "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>, wang jun <availa@outlook.com>, Nehal Shah <Nehal-bakulchandra.Shah@amd.com>, Shyam Sundar S K <Shyam-sundar.S-k@amd.com>, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? Date: Tue, 3 Nov 2020 12:00:34 +0100 [thread overview] Message-ID: <6a8a246b-1b11-f569-b495-6440e70fc121@redhat.com> (raw) In-Reply-To: <CAHp75VdYhe4YEAzULMNkhihTQwHAP3fC2F6iD=datqzyzd=4fQ@mail.gmail.com> Hi, On 11/3/20 11:49 AM, Andy Shevchenko wrote: > On Tue, Nov 3, 2020 at 12:12 PM Hans de Goede <hdegoede@redhat.com> wrote: >> On 11/3/20 1:05 AM, Coiby Xu wrote: >>> On Tue, Oct 27, 2020 at 11:09:11AM +0100, Hans de Goede wrote: > > ... > >>> [1] https://lore.kernel.org/patchwork/comment/1522675/ >> >> This is a case where Andy is obviously right and you should just use the >> higher precision "unit = 15625" value (except probably that is wrong too, >> see below). >> >> We have had similar issues with the docs for getting the TSC frequency >> on some Intel chips, where the docs said 16.6 MHz for a certain register >> value, where what they meant was 100/6 MHz which really is significantly >> different. This was leading to a time drift of 5 minutes / day on non >> networked (so no NTP) Linux systems. >> >> I think this is what Andy was referring to when he wrote: >> "What the heck with HW companies! (Just an emotion based on the experience)" > > Exactly! > > ... > >> Actually all the values look somewhat suspect. The comment: >> >>> Debounce Debounce Timer Max >>> TmrLarge TmrOutUnit Unit Debounce >>> Time >>> 0 0 61 usec (2 RtcClk) 976 usec >>> 0 1 244 usec (8 RtcClk) 3.9 msec >>> 1 0 15.6 msec (512 RtcClk) 250 msec >>> 1 1 62.5 msec (2048 RtcClk) 1 sec >> >> Helpfully gives the values in RtcClks. A typical RTC clock crystal >> is 32 KHz which gives us 31.25 usec per tick, so I would expect the >> values to be: > > I guess you are mistaken here. Usual frequency for RTC is 32.768kHz > [1], which gives more or less above values > > 30.51757 > 61.03515 > 244.14062 > 15625 > 62500 You are completely right, my bad. > [1]: https://en.wikipedia.org/wiki/Real-time_clock > (just google: rtc clock frequency) I did duckduckgo, but one of the first hits said 32KHz crystal and I assumed that meant 32.000 KHz falling into the exact precision trap I was complaining about in my previous email, oops. Regards, Hans
WARNING: multiple messages have this Message-ID (diff)
From: Hans de Goede <hdegoede@redhat.com> To: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>, Linus Walleij <linus.walleij@linaro.org>, Coiby Xu <coiby.xu@gmail.com>, wang jun <availa@outlook.com>, "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>, linux-kernel-mentees@lists.linuxfoundation.org, Nehal Shah <Nehal-bakulchandra.Shah@amd.com> Subject: Re: [Linux-kernel-mentees] Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? Date: Tue, 3 Nov 2020 12:00:34 +0100 [thread overview] Message-ID: <6a8a246b-1b11-f569-b495-6440e70fc121@redhat.com> (raw) In-Reply-To: <CAHp75VdYhe4YEAzULMNkhihTQwHAP3fC2F6iD=datqzyzd=4fQ@mail.gmail.com> Hi, On 11/3/20 11:49 AM, Andy Shevchenko wrote: > On Tue, Nov 3, 2020 at 12:12 PM Hans de Goede <hdegoede@redhat.com> wrote: >> On 11/3/20 1:05 AM, Coiby Xu wrote: >>> On Tue, Oct 27, 2020 at 11:09:11AM +0100, Hans de Goede wrote: > > ... > >>> [1] https://lore.kernel.org/patchwork/comment/1522675/ >> >> This is a case where Andy is obviously right and you should just use the >> higher precision "unit = 15625" value (except probably that is wrong too, >> see below). >> >> We have had similar issues with the docs for getting the TSC frequency >> on some Intel chips, where the docs said 16.6 MHz for a certain register >> value, where what they meant was 100/6 MHz which really is significantly >> different. This was leading to a time drift of 5 minutes / day on non >> networked (so no NTP) Linux systems. >> >> I think this is what Andy was referring to when he wrote: >> "What the heck with HW companies! (Just an emotion based on the experience)" > > Exactly! > > ... > >> Actually all the values look somewhat suspect. The comment: >> >>> Debounce Debounce Timer Max >>> TmrLarge TmrOutUnit Unit Debounce >>> Time >>> 0 0 61 usec (2 RtcClk) 976 usec >>> 0 1 244 usec (8 RtcClk) 3.9 msec >>> 1 0 15.6 msec (512 RtcClk) 250 msec >>> 1 1 62.5 msec (2048 RtcClk) 1 sec >> >> Helpfully gives the values in RtcClks. A typical RTC clock crystal >> is 32 KHz which gives us 31.25 usec per tick, so I would expect the >> values to be: > > I guess you are mistaken here. Usual frequency for RTC is 32.768kHz > [1], which gives more or less above values > > 30.51757 > 61.03515 > 244.14062 > 15625 > 62500 You are completely right, my bad. > [1]: https://en.wikipedia.org/wiki/Real-time_clock > (just google: rtc clock frequency) I did duckduckgo, but one of the first hits said 32KHz crystal and I assumed that meant 32.000 KHz falling into the exact precision trap I was complaining about in my previous email, oops. Regards, Hans _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
next prev parent reply other threads:[~2020-11-03 11:00 UTC|newest] Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-01 13:22 Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? Coiby Xu 2020-10-01 13:22 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-01 20:57 ` Linus Walleij 2020-10-01 20:57 ` [Linux-kernel-mentees] " Linus Walleij 2020-10-02 9:40 ` Hans de Goede 2020-10-02 9:40 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-02 12:42 ` Coiby Xu 2020-10-02 12:42 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-02 13:36 ` Hans de Goede 2020-10-02 13:36 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-02 14:51 ` Coiby Xu 2020-10-02 14:51 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-02 19:44 ` Hans de Goede 2020-10-02 19:44 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-02 22:45 ` Coiby Xu 2020-10-02 22:45 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-03 13:22 ` Hans de Goede 2020-10-03 13:22 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-03 23:03 ` Coiby Xu 2020-10-03 23:03 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-04 5:16 ` Coiby Xu 2020-10-04 5:16 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 4:49 ` Coiby Xu 2020-10-06 4:49 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 6:28 ` Hans de Goede 2020-10-06 6:28 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-06 8:31 ` Coiby Xu 2020-10-06 8:31 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 8:55 ` Hans de Goede 2020-10-06 8:55 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-06 9:28 ` Hans de Goede 2020-10-06 9:28 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-06 9:29 ` Hans de Goede 2020-10-06 9:29 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-08 16:32 ` Coiby Xu 2020-10-08 16:32 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-14 4:24 ` Coiby Xu 2020-10-14 4:24 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-14 11:34 ` Coiby Xu 2020-10-14 11:34 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-14 11:46 ` Hans de Goede 2020-10-14 11:46 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-15 3:27 ` Coiby Xu 2020-10-15 3:27 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-15 4:06 ` Coiby Xu 2020-10-15 4:06 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-26 22:54 ` Coiby Xu 2020-10-26 22:54 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-27 9:52 ` Andy Shevchenko 2020-10-27 9:52 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-10-30 4:58 ` Coiby Xu 2020-10-30 4:58 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-27 10:09 ` Hans de Goede 2020-10-27 10:09 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-27 15:13 ` Andy Shevchenko 2020-10-27 15:13 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-10-27 16:00 ` Hans de Goede 2020-10-27 16:00 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-27 16:09 ` Andy Shevchenko 2020-10-27 16:09 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-10-29 8:04 ` Mika Westerberg 2020-10-29 8:04 ` [Linux-kernel-mentees] " Mika Westerberg 2020-10-30 4:54 ` Coiby Xu 2020-10-30 4:54 ` [Linux-kernel-mentees] " Coiby Xu 2020-11-02 19:06 ` Andy Shevchenko 2020-11-02 19:06 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-11-02 22:56 ` Coiby Xu 2020-11-02 22:56 ` [Linux-kernel-mentees] " Coiby Xu 2020-11-03 0:05 ` Coiby Xu 2020-11-03 0:05 ` [Linux-kernel-mentees] " Coiby Xu 2020-11-03 10:12 ` Hans de Goede 2020-11-03 10:12 ` [Linux-kernel-mentees] " Hans de Goede 2020-11-03 10:49 ` Andy Shevchenko 2020-11-03 10:49 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-11-03 11:00 ` Hans de Goede [this message] 2020-11-03 11:00 ` Hans de Goede 2020-10-08 16:26 ` Coiby Xu 2020-10-08 16:26 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 9:16 ` Linus Walleij 2020-10-06 9:16 ` [Linux-kernel-mentees] " Linus Walleij 2020-10-08 16:40 ` Coiby Xu 2020-10-08 16:40 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-02 10:59 ` Coiby Xu 2020-10-02 10:59 ` [Linux-kernel-mentees] " Coiby Xu
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=6a8a246b-1b11-f569-b495-6440e70fc121@redhat.com \ --to=hdegoede@redhat.com \ --cc=Nehal-bakulchandra.Shah@amd.com \ --cc=Shyam-sundar.S-k@amd.com \ --cc=andy.shevchenko@gmail.com \ --cc=availa@outlook.com \ --cc=coiby.xu@gmail.com \ --cc=linus.walleij@linaro.org \ --cc=linux-gpio@vger.kernel.org \ --cc=linux-kernel-mentees@lists.linuxfoundation.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.