From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Tuowen Zhao <ztuowen@gmail.com>
Cc: lee.jones@linaro.org, linux-kernel@vger.kernel.org,
andriy.shevchenko@linux.intel.com, acelan.kao@canonical.com,
bhelgaas@google.com, kai.heng.feng@canonical.com,
mcgrof@kernel.org
Subject: Re: [PATCH v2] mfd: intel-lpss: use devm_ioremap_uc for MMIO
Date: Tue, 8 Oct 2019 12:18:04 +0300 [thread overview]
Message-ID: <20191008091804.GB2819@lahna.fi.intel.com> (raw)
In-Reply-To: <20191007184231.13256-1-ztuowen@gmail.com>
On Mon, Oct 07, 2019 at 12:42:31PM -0600, Tuowen Zhao wrote:
> Some BIOS erroneously specifies write-combining BAR for intel-lpss-pci
> in MTRR. This will cause the system to hang during boot. If possible,
> this bug could be corrected with a firmware update.
>
> This patch adds devm_ioremap_uc as a new managed wrapper to ioremap_uc
> and with it overwrite the MTRR settings to force the use of strongly
> uncachable pages for intel-lpss.
>
> The BIOS bug is present on Dell XPS 13 7390 2-in-1:
>
> [ 0.001734] 5 base 4000000000 mask 6000000000 write-combining
>
> 4000000000-7fffffffff : PCI Bus 0000:00
> 4000000000-400fffffff : 0000:00:02.0 (i915)
> 4010000000-4010000fff : 0000:00:15.0 (intel-lpss-pci)
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485
> Signed-off-by: Tuowen Zhao <ztuowen@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
next prev parent reply other threads:[~2019-10-08 9:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 18:42 [PATCH v2] mfd: intel-lpss: use devm_ioremap_uc for MMIO Tuowen Zhao
2019-10-08 3:10 ` AceLan Kao
2019-10-08 9:18 ` Mika Westerberg [this message]
2019-10-08 13:58 ` Andy Shevchenko
2019-10-08 15:16 ` Luis Chamberlain
2019-10-08 16:12 ` Andy Shevchenko
[not found] ` <CAB=NE6V64g5WLMYFxkpC_wsnSbGG-5Nn9uFo1zpcqjP9NsRB+w@mail.gmail.com>
2019-10-08 21:07 ` GMAIL
2019-10-09 6:28 ` Andy Shevchenko
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