Hi Jon, thanks for replying
-----Original Message----- From: Jon Masters [mailto:jcm@redhat.com] Sent: 21 December 2015 23:11 To: Arnd Bergmann Cc: Gabriele Paoloni; Tomasz Nowicki; bhelgaas@google.com; will.deacon@arm.com; catalin.marinas@arm.com; rjw@rjwysocki.net; hanjun.guo@linaro.org; Lorenzo.Pieralisi@arm.com; okaya@codeaurora.org; jiang.liu@linux.intel.com; Stefano.Stabellini@eu.citrix.com; robert.richter@caviumnetworks.com; mw@semihalf.com; Liviu.Dudau@arm.com; ddaney@caviumnetworks.com; tglx@linutronix.de; Wangyijing; Suravee.Suthikulpanit@amd.com; msalter@redhat.com; linux- pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux- acpi@vger.kernel.org; linux-kernel@vger.kernel.org; linaro- acpi@lists.linaro.org; jchandra@broadcom.com Subject: Re: [PATCH V2 22/23] pci, acpi: Match PCI config space accessors against platfrom specific quirks.
Sorry for top-posting. A quick note that SMBIOS3 is required by SBBR so it can be presumed that compliant platforms will provide quirks via DMI.
Ok so you completely clarified my question 1). Many Thanks for this
Gab
-- Computer Architect | Sent from my 64-bit #ARM Powered phone
On Dec 21, 2015, at 09:11, Arnd Bergmann arnd@arndb.de wrote:
On Monday 21 December 2015, Gabriele Paoloni wrote:
-----Original Message----- From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel- owner@vger.kernel.org] On Behalf Of Tomasz Nowicki
Some platforms may not be fully compliant with generic set of PCI config accessors. For these cases we implement the way to overwrite accessors set before PCI buses enumeration. Algorithm that
overwrite
accessors matches against platform ID (DMI), domain and bus number, hopefully enough for all cases. All quirks can be defined using: DECLARE_ACPI_MCFG_FIXUP() and keep self contained.
I've got a couple of comments/questions about this patch..
- So according to this mechanism quirks would be supported only by
vendors whose BIOS are SMBIOS compliant. Now personally I am ok with this but I don't know if this is OK in general as it would narrow down the number of platforms that would be able to define the quirks... Lorenzo, Arnd what is your opinion here?
I'd rather not see the quirks in mainline at all, and only support SBSA compliant machines, or require the BIOS to work around the hardware quirks differently (e.g. by trapping config space access through secure firmware, or going through an AML method to be defined). I'm certainly ok with making it depend on SMBIOS if we are
going to use something like this.
Arnd