From: Henrik Rydberg <rydberg@bitmath.org>
To: Brad Campbell <brad@fnarfbargle.com>, linux-hwmon@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
hns@goldelico.com, Andreas Kemnade <andreas@kemnade.info>,
Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>
Subject: Re: [PATCH v5 1/1] applesmc: Re-work SMC comms
Date: Wed, 11 Nov 2020 21:05:59 +0100 [thread overview]
Message-ID: <29b03865-f00a-f121-b7a5-c4b9179a27cb@bitmath.org> (raw)
In-Reply-To: <8c525b3b-b4a6-8ee4-8128-a20e0ad408e4@fnarfbargle.com>
On 2020-11-11 14:06, Brad Campbell wrote:
> Commit fff2d0f701e6 ("hwmon: (applesmc) avoid overlong udelay()")
> introduced an issue whereby communication with the SMC became
> unreliable with write errors like :
>
> [ 120.378614] applesmc: send_byte(0x00, 0x0300) fail: 0x40
> [ 120.378621] applesmc: LKSB: write data fail
> [ 120.512782] applesmc: send_byte(0x00, 0x0300) fail: 0x40
> [ 120.512787] applesmc: LKSB: write data fail
>
> The original code appeared to be timing sensitive and was not reliable
> with the timing changes in the aforementioned commit.
>
> This patch re-factors the SMC communication to remove the timing
> dependencies and restore function with the changes previously
> committed. Logic changes based on inspection of the Apple SMC kext.
>
> Tested on : MacbookAir6,2 MacBookPro11,1 iMac12,2, MacBookAir1,1,
> MacBookAir3,1
>
> Fixes: fff2d0f701e6 ("hwmon: (applesmc) avoid overlong udelay()")
> Reported-by: Andreas Kemnade <andreas@kemnade.info>
> Tested-by: Andreas Kemnade <andreas@kemnade.info> # MacBookAir6,2
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Brad Campbell <brad@fnarfbargle.com>
> Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
>
> ---
> Changelog :
> v1 : Initial attempt
> v2 : Address logic and coding style
> v3 : Removed some debug hangover. Added tested-by. Modifications for MacBookAir1,1
> v4 : Re-factored logic based on Apple driver. Simplified wait_status loop
> v5 : Re-wrote status loop. Simplified busy check in send_byte(). Fixed formatting
Hi Brad,
This version is still working fine on the MBA1,1, at 50 reads per second.
Thanks,
Henrik
next prev parent reply other threads:[~2020-11-11 20:05 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 8:54 [REGRESSION] hwmon: (applesmc) avoid overlong udelay() Andreas Kemnade
2020-09-30 16:44 ` Guenter Roeck
2020-09-30 20:00 ` Arnd Bergmann
2020-10-01 22:22 ` Andreas Kemnade
2020-10-02 4:07 ` Guenter Roeck
2020-10-06 7:02 ` Andreas Kemnade
2020-11-02 23:56 ` Brad Campbell
2020-11-03 5:56 ` Brad Campbell
2020-11-04 13:20 ` Andreas Kemnade
2020-11-05 2:18 ` Brad Campbell
2020-11-05 4:22 ` Brad Campbell
2020-11-05 4:43 ` Guenter Roeck
2020-11-05 5:05 ` Brad Campbell
2020-11-05 5:26 ` Guenter Roeck
2020-11-05 5:47 ` [PATCH] applesmc: Re-work SMC comms v1 Brad Campbell
2020-11-05 7:26 ` [PATCH] applesmc: Re-work SMC comms v2 Brad Campbell
2020-11-05 7:56 ` Henrik Rydberg
2020-11-05 8:15 ` Andreas Kemnade
2020-11-05 8:30 ` Brad Campbell
2020-11-05 10:31 ` Henrik Rydberg
2020-11-06 16:26 ` Henrik Rydberg
2020-11-06 20:02 ` Henrik Rydberg
2020-11-07 18:31 ` Henrik Rydberg
2020-11-08 0:09 ` Brad Campbell
2020-11-08 8:22 ` Henrik Rydberg
2020-11-08 1:00 ` [PATCH v3] applesmc: Re-work SMC comms Brad Campbell
2020-11-08 8:35 ` Henrik Rydberg
2020-11-08 10:14 ` Henrik Rydberg
2020-11-08 11:57 ` Brad Campbell
2020-11-08 12:04 ` Henrik Rydberg
2020-11-09 13:06 ` Brad Campbell
2020-11-09 17:08 ` Henrik Rydberg
2020-11-09 22:52 ` Brad Campbell
2020-11-08 16:06 ` Guenter Roeck
2020-11-09 0:25 ` Brad Campbell
2020-11-10 2:04 ` Brad Campbell
2020-11-10 4:55 ` Guenter Roeck
2020-11-10 5:40 ` Brad Campbell
2020-11-10 16:02 ` Guenter Roeck
2020-11-09 8:44 ` Andreas Kemnade
2020-11-09 9:51 ` Brad Campbell
2020-11-11 3:37 ` [PATCH v4 0/1] " Brad Campbell
2020-11-11 4:55 ` [PATCH v1] applesmc: Cleanups on top of re-work comms Brad Campbell
2020-11-11 3:38 ` [PATCH v4 1/1] applesmc: Re-work SMC comms Brad Campbell
2020-11-11 5:56 ` Guenter Roeck
2020-11-11 7:05 ` Brad Campbell
2020-11-11 13:06 ` [PATCH v5 " Brad Campbell
2020-11-11 20:05 ` Henrik Rydberg [this message]
2020-11-11 23:28 ` Brad Campbell
2020-11-12 3:08 ` [PATCH v6 " Brad Campbell
2020-11-12 17:20 ` Guenter Roeck
2020-11-06 23:11 ` [PATCH] applesmc: Re-work SMC comms v2 Brad Campbell
2020-11-05 8:12 ` Andreas Kemnade
2020-11-05 16:12 ` Guenter Roeck
2020-11-06 0:02 ` Brad Campbell
2020-11-06 3:08 ` Guenter Roeck
2020-11-09 9:27 ` [PATCH] applesmc: Re-work SMC comms v1 kernel test robot
2020-11-05 9:48 ` [REGRESSION] hwmon: (applesmc) avoid overlong udelay() Arnd Bergmann
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