From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:49226 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753853AbdGUWPS (ORCPT ); Fri, 21 Jul 2017 18:15:18 -0400 Subject: Re: [PATCH v3 2/2] i2c: designware: Some broken DSTDs use 1MiHz instead of 1MHz To: Andy Shevchenko , Jarkko Nikula , Wolfram Sang , Mika Westerberg Cc: linux-i2c@vger.kernel.org, stable@vger.kernel.org References: <20170713134502.10816-1-hdegoede@redhat.com> <20170713134502.10816-2-hdegoede@redhat.com> <1500213858.29303.20.camel@linux.intel.com> From: Hans de Goede Message-ID: Date: Sat, 22 Jul 2017 00:15:16 +0200 MIME-Version: 1.0 In-Reply-To: <1500213858.29303.20.camel@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: Hi, On 16-07-17 16:04, Andy Shevchenko wrote: > On Thu, 2017-07-13 at 15:45 +0200, Hans de Goede wrote: >> At least the Acer Iconia Tab8 / aka W1-810 uses 1MiHz instead of >> 1MHz for one of its busses, fix this up to 1MHz instead of failing >> the probe of that bus. >> >> This fixes the accelerometer on the Acer Iconia Tab8 not working. >> > > Should it have a Fixes tag? No I don't think so, as this worksaround a firmware bug the original commit introducing the check is not really fixed by this, as the original commit is fine really. Regards, Hans > > Reviewed-by: Andy Shevchenko > > (on condition Jarkko and Wolfram are okay with this; in the future it > would be better to have a list of possible speeds and algo that chooses > one based on FW configuration) > >> Cc: stable@vger.kernel.org >> Signed-off-by: Hans de Goede >> --- >> drivers/i2c/busses/i2c-designware-platdrv.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c >> b/drivers/i2c/busses/i2c-designware-platdrv.c >> index d139b156f9c9..143a8fd582b4 100644 >> --- a/drivers/i2c/busses/i2c-designware-platdrv.c >> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c >> @@ -298,6 +298,9 @@ static int dw_i2c_plat_probe(struct >> platform_device *pdev) >> } >> >> acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); >> + /* Some broken DSTDs use 1MiHz instead of 1MHz */ >> + if (acpi_speed == 1048576) >> + acpi_speed = 1000000; >> /* >> * Find bus speed from the "clock-frequency" device property, >> ACPI >> * or by using fast mode if neither is set. >