From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hanjun Guo Subject: Re: [PATCH v10 3/4] ARM64: ACPI: enable ACPI_SPCR_TABLE Date: Fri, 9 Sep 2016 17:28:51 +0800 Message-ID: <706e4bc9-1010-ba2d-55ec-dc6f24611bd3@linaro.org> References: <20160905123617.18775-1-aleksey.makarov@linaro.org> <20160905123617.18775-4-aleksey.makarov@linaro.org> <7e5486cc-4080-2d1e-8f6d-98874379887d@gmail.com> <20160908111654.GH1493@arm.com> <1473352456.21193.8.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f53.google.com ([209.85.220.53]:33962 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753480AbcIIJ27 (ORCPT ); Fri, 9 Sep 2016 05:28:59 -0400 Received: by mail-pa0-f53.google.com with SMTP id to9so26736024pac.1 for ; Fri, 09 Sep 2016 02:28:58 -0700 (PDT) In-Reply-To: <1473352456.21193.8.camel@redhat.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Mark Salter , Will Deacon , Aleksey Makarov Cc: Catalin Marinas , Aleksey Makarov , "Rafael J . Wysocki" , "Zheng, Lv" , Kefeng Wang , Russell King , Peter Hurley , Graeme Gregory , Greg Kroah-Hartman , Andy Shevchenko , linux-kernel@vger.kernel.org, Leif Lindholm , linux-acpi@vger.kernel.org, Yury Norov , Christopher Covington , linux-serial@vger.kernel.org, Al Stone , linux-arm-kernel@lists.infradead.org, Len Brown On 2016/9/9 0:34, Mark Salter wrote: > On Thu, 2016-09-08 at 12:16 +0100, Will Deacon wrote: >> On Wed, Sep 07, 2016 at 12:30:19PM +0300, Aleksey Makarov wrote: >>> >>> >>> On 09/05/2016 03:36 PM, Aleksey Makarov wrote: >>>> >>>> SBBR mentions SPCR as a mandatory ACPI table. So enable it for ARM64 >>>> >>>> Earlycon should be set up as early as possible. ACPI boot tables are >>>> mapped in arch/arm64/kernel/acpi.c:acpi_boot_table_init() that >>>> is called from setup_arch() and that's where we parse SPCR. >>>> So it has to be opted-in per-arch. >>>> >>>> When ACPI_SPCR_TABLE is defined initialization of DT earlycon is >>>> deferred until the DT/ACPI decision is done. Initialize DT earlycon >>>> if ACPI is disabled. >>> Hi Will, Catalin, >>> >>> Can you review this patch and consider ACKing it please? >> Hanjun, Al, Mark, Graeme -- any comments on this? >> >> Will > > I think there is a problem still with systems using 32-bit access to 8250 > UARTs (i.e. Mustang) but that will need a DBG2 table spec change and > followup patch to resolve. Hmm, I think you mean we can add patches later with the spec updated, and this patch works with SBSA pl011 can go for now? Thanks Hanjun From mboxrd@z Thu Jan 1 00:00:00 1970 From: hanjun.guo@linaro.org (Hanjun Guo) Date: Fri, 9 Sep 2016 17:28:51 +0800 Subject: [PATCH v10 3/4] ARM64: ACPI: enable ACPI_SPCR_TABLE In-Reply-To: <1473352456.21193.8.camel@redhat.com> References: <20160905123617.18775-1-aleksey.makarov@linaro.org> <20160905123617.18775-4-aleksey.makarov@linaro.org> <7e5486cc-4080-2d1e-8f6d-98874379887d@gmail.com> <20160908111654.GH1493@arm.com> <1473352456.21193.8.camel@redhat.com> Message-ID: <706e4bc9-1010-ba2d-55ec-dc6f24611bd3@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2016/9/9 0:34, Mark Salter wrote: > On Thu, 2016-09-08 at 12:16 +0100, Will Deacon wrote: >> On Wed, Sep 07, 2016 at 12:30:19PM +0300, Aleksey Makarov wrote: >>> >>> >>> On 09/05/2016 03:36 PM, Aleksey Makarov wrote: >>>> >>>> SBBR mentions SPCR as a mandatory ACPI table. So enable it for ARM64 >>>> >>>> Earlycon should be set up as early as possible. ACPI boot tables are >>>> mapped in arch/arm64/kernel/acpi.c:acpi_boot_table_init() that >>>> is called from setup_arch() and that's where we parse SPCR. >>>> So it has to be opted-in per-arch. >>>> >>>> When ACPI_SPCR_TABLE is defined initialization of DT earlycon is >>>> deferred until the DT/ACPI decision is done. Initialize DT earlycon >>>> if ACPI is disabled. >>> Hi Will, Catalin, >>> >>> Can you review this patch and consider ACKing it please? >> Hanjun, Al, Mark, Graeme -- any comments on this? >> >> Will > > I think there is a problem still with systems using 32-bit access to 8250 > UARTs (i.e. Mustang) but that will need a DBG2 table spec change and > followup patch to resolve. Hmm, I think you mean we can add patches later with the spec updated, and this patch works with SBSA pl011 can go for now? Thanks Hanjun