From mboxrd@z Thu Jan 1 00:00:00 1970 From: Graeme Gregory Subject: Re: [PATCH 1/8] arm64: move acpi/dt decision earlier in boot process Date: Tue, 23 Feb 2016 13:57:31 +0000 Message-ID: <20160223135731.GA24781@xora-haswell.xora.org.uk> References: <1456148818-26257-1-git-send-email-aleksey.makarov@linaro.org> <1456148818-26257-2-git-send-email-aleksey.makarov@linaro.org> <56CB2D0D.3090408@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <56CB2D0D.3090408@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Matthias Brugger Cc: Aleksey Makarov , linux-acpi@vger.kernel.org, Russell King , Graeme Gregory , Greg Kroah-Hartman , "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, Leif Lindholm , Christopher Covington , linux-serial@vger.kernel.org, Catalin Marinas , Will Deacon , Al Stone , linux-arm-kernel@lists.infradead.org List-Id: linux-acpi@vger.kernel.org On Mon, Feb 22, 2016 at 04:45:17PM +0100, Matthias Brugger wrote: > > > On 22/02/16 14:46, Aleksey Makarov wrote: > >From: Leif Lindholm > > > >In order to support selecting earlycon via either ACPI or DT, move > >the decision on whether to attempt ACPI configuration into the > >early_param handling. Then make acpi_boot_table_init() bail out if > >acpi_disabled. > > > >Signed-off-by: Leif Lindholm > >--- > > arch/arm64/kernel/acpi.c | 54 ++++++++++++++++++++++++++---------------------- > > 1 file changed, 29 insertions(+), 25 deletions(-) > > > >diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > >index d1ce8e2..7a944f7 100644 > >--- a/arch/arm64/kernel/acpi.c > >+++ b/arch/arm64/kernel/acpi.c > >@@ -44,6 +44,19 @@ EXPORT_SYMBOL(acpi_pci_disabled); > > static bool param_acpi_off __initdata; > > static bool param_acpi_force __initdata; > > > >+static int __init dt_scan_depth1_nodes(unsigned long node, > >+ const char *uname, int depth, > >+ void *data) > >+{ > >+ /* > >+ * Return 1 as soon as we encounter a node at depth 1 that is > >+ * not the /chosen node. > >+ */ > >+ if (depth == 1 && (strcmp(uname, "chosen") != 0)) > >+ return 1; > >+ return 0; > >+} > >+ > > static int __init parse_acpi(char *arg) > > { > > if (!arg) > >@@ -57,23 +70,27 @@ static int __init parse_acpi(char *arg) > > else > > return -EINVAL; /* Core will print when we return error */ > > > >- return 0; > >-} > >-early_param("acpi", parse_acpi); > >+ /* > >+ * Enable ACPI instead of device tree unless > >+ * - ACPI has been disabled explicitly (acpi=off), or > >+ * - the device tree is not empty (it has more than just a /chosen node) > >+ * and ACPI has not been force enabled (acpi=force) > >+ */ > >+ if (param_acpi_off || > >+ (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) > >+ return 0; > > > >-static int __init dt_scan_depth1_nodes(unsigned long node, > >- const char *uname, int depth, > >- void *data) > >-{ > > /* > >- * Return 1 as soon as we encounter a node at depth 1 that is > >- * not the /chosen node. > >+ * ACPI is disabled at this point. Enable it in order to parse > >+ * the ACPI tables and carry out sanity checks > > */ > >- if (depth == 1 && (strcmp(uname, "chosen") != 0)) > >- return 1; > >+ enable_acpi(); > >+ > > So we only enable ACPI if we pass acpi=force as kernel parameter? > I'm not sure if this is what you wanted to do. > The current preference from ARM64 maintainers was that is both ACPI tables and a DT were presented then DT should take precedence. With no DT provided the code should use ACPI. Graeme From mboxrd@z Thu Jan 1 00:00:00 1970 From: gg@slimlogic.co.uk (Graeme Gregory) Date: Tue, 23 Feb 2016 13:57:31 +0000 Subject: [PATCH 1/8] arm64: move acpi/dt decision earlier in boot process In-Reply-To: <56CB2D0D.3090408@gmail.com> References: <1456148818-26257-1-git-send-email-aleksey.makarov@linaro.org> <1456148818-26257-2-git-send-email-aleksey.makarov@linaro.org> <56CB2D0D.3090408@gmail.com> Message-ID: <20160223135731.GA24781@xora-haswell.xora.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Feb 22, 2016 at 04:45:17PM +0100, Matthias Brugger wrote: > > > On 22/02/16 14:46, Aleksey Makarov wrote: > >From: Leif Lindholm > > > >In order to support selecting earlycon via either ACPI or DT, move > >the decision on whether to attempt ACPI configuration into the > >early_param handling. Then make acpi_boot_table_init() bail out if > >acpi_disabled. > > > >Signed-off-by: Leif Lindholm > >--- > > arch/arm64/kernel/acpi.c | 54 ++++++++++++++++++++++++++---------------------- > > 1 file changed, 29 insertions(+), 25 deletions(-) > > > >diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > >index d1ce8e2..7a944f7 100644 > >--- a/arch/arm64/kernel/acpi.c > >+++ b/arch/arm64/kernel/acpi.c > >@@ -44,6 +44,19 @@ EXPORT_SYMBOL(acpi_pci_disabled); > > static bool param_acpi_off __initdata; > > static bool param_acpi_force __initdata; > > > >+static int __init dt_scan_depth1_nodes(unsigned long node, > >+ const char *uname, int depth, > >+ void *data) > >+{ > >+ /* > >+ * Return 1 as soon as we encounter a node at depth 1 that is > >+ * not the /chosen node. > >+ */ > >+ if (depth == 1 && (strcmp(uname, "chosen") != 0)) > >+ return 1; > >+ return 0; > >+} > >+ > > static int __init parse_acpi(char *arg) > > { > > if (!arg) > >@@ -57,23 +70,27 @@ static int __init parse_acpi(char *arg) > > else > > return -EINVAL; /* Core will print when we return error */ > > > >- return 0; > >-} > >-early_param("acpi", parse_acpi); > >+ /* > >+ * Enable ACPI instead of device tree unless > >+ * - ACPI has been disabled explicitly (acpi=off), or > >+ * - the device tree is not empty (it has more than just a /chosen node) > >+ * and ACPI has not been force enabled (acpi=force) > >+ */ > >+ if (param_acpi_off || > >+ (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) > >+ return 0; > > > >-static int __init dt_scan_depth1_nodes(unsigned long node, > >- const char *uname, int depth, > >- void *data) > >-{ > > /* > >- * Return 1 as soon as we encounter a node at depth 1 that is > >- * not the /chosen node. > >+ * ACPI is disabled at this point. Enable it in order to parse > >+ * the ACPI tables and carry out sanity checks > > */ > >- if (depth == 1 && (strcmp(uname, "chosen") != 0)) > >- return 1; > >+ enable_acpi(); > >+ > > So we only enable ACPI if we pass acpi=force as kernel parameter? > I'm not sure if this is what you wanted to do. > The current preference from ARM64 maintainers was that is both ACPI tables and a DT were presented then DT should take precedence. With no DT provided the code should use ACPI. Graeme