Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932474Ab3DBKoT (ORCPT ); Tue, 2 Apr 2013 06:44:19 -0400 Received: from mail-ea0-f178.google.com ([209.85.215.178]:58905 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760203Ab3DBKoQ (ORCPT ); Tue, 2 Apr 2013 06:44:16 -0400 Message-ID: <515AB67A.8010206@amarulasolutions.com> Date: Tue, 02 Apr 2013 12:44:10 +0200 From: Michael Trimarchi Organization: Amarula Solutions User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Sourav Poddar CC: Kevin Hilman , Santosh Shilimkar , Felipe Balbi , Rajendra nayak , tony@atomide.com, rmk+kernel@arm.linux.org.uk, linux-serial@vger.kernel.org, LKML , linux-omap@vger.kernel.org Subject: Re: [PATCH/Resend 2/2] arm: mach-omap2: prevent UART console idle on suspend while using "no_console_suspend" References: <1363612924-349-1-git-send-email-sourav.poddar@ti.com> <87fvzsilnv.fsf@linaro.org> <5149A221.5@ti.com> <5149A63C.4000102@ti.com> <515AA9CD.5000004@ti.com> <515AADB7.3080906@amarulasolutions.com> <515AB579.7010705@ti.com> In-Reply-To: <515AB579.7010705@ti.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7369 Lines: 167 Hi On 02/04/13 12:39, Sourav Poddar wrote: > Hi, > On Tuesday 02 April 2013 03:36 PM, Michael Trimarchi wrote: >> Hi >> >> On 02/04/13 11:50, Sourav Poddar wrote: >>> Hi Kevin, >>> On Wednesday 20 March 2013 05:36 PM, Sourav Poddar wrote: >>>> Realised the list to whom the patch was send got dropped. Ccing them all.. >>>> On Wednesday 20 March 2013 05:18 PM, Sourav Poddar wrote: >>>>> Hi Kevin, >>>>> On Tuesday 19 March 2013 12:24 AM, Kevin Hilman wrote: >>>>>> Sourav Poddar writes: >>>>>> >>>>>>> With dt boot, uart wakeup after suspend is non functional on omap4/5 while using >>>>>>> "no_console_suspend" in the bootargs. With "no_console_suspend" used, od->flags >>>>>>> should be ORed with "OMAP_DEVICE_NO_IDLE_ON_SUSPEND", thereby not allowing the console >>>>>>> to idle in the suspend path. For non-dt case, this was taken care by platform data. >>>>>>> >>>>>>> Tested on omap5430evm, omap4430sdp. >>>>>>> >>>>>>> Cc: Santosh Shilimkar >>>>>>> Cc: Felipe Balbi >>>>>>> Cc: Rajendra nayak >>>>>>> Signed-off-by: Sourav Poddar >>>>>> This patch creates a dependency between omap_device (generic, >>>>>> device-independent code) and a specific driver (UART.) >>>>>> >>>>>> If you need to do something like this that's DT boot specific, then >>>>>> we probably need some late initcall in serial.c to handle this. It does >>>>>> not belong in omap_device. >>>>>> >>>>> The following function "omap_device_disable_idle_on_suspend(pdev)" should only >>>>> be called once the omap device has been build, which in the case of device tree is >>>>> done in omap_device.c file. Moreover, the above call should be executed conditionally >>>>> and should depend on the following two parameter. >>>>> >>>>> [1] a. Whether "no_console_suspend" is set and >>>>> b. the device build is a console uart. >>>>> >>>>> When I look closely into the serial.c file, I realised that >>>>> "core_initcall(omap_serial_early_init)" gets called irrespective >>>>> of dt/non dt boot and will take care of most of the stuff(checking whether >>>>> "no_console_suspend" is used and which uart is used as a console uart) which the >>>>> $subject patch is proposing. >>>>> >>>>> But the problem is that we need to exchange the parsed information >>>>> from serial.c to the omap_device file for the condtional execution of >>>>> "omap_device_disable_idle_on_suspend" >>>>> >>>>> In this case, >>>>> from "serial.c" we need >>>>> 1. no_console_suspend = true >>>>> 2. strcpy(console_name, oh_name), where oh_name corresponds to the console uart. >>>>> >>>>> then in "omap_device.c" do >>>>> if (no_console_suspend&& !strcmp(oh->name, console_name)) >>>>> omap_device_disable_idle_on_suspend(pdev); >>>>> >>>>> Please correct if I am understanding it incorrectly. >>>>> >>>>> If the above understanding looks good to you, is there a way we can make this >>>>> exchange of information happen between serial.c and omap_device.c file? >>> Any input on this? >>> As I explained earlier, that there is a need to parse information in serial.c and use that in >>> omap_device.c only after the device is build. >>> >>> Below is the patch (inlined) which further explains my point. The patch is "just for the >>> idea" I am trying to express. >>> I have used extern variables to exchange information between serial.c and omap_device.c. >>> Is there is a better way, we can do this "information exchange" without using extern variables? >>> >>> >>> ----- >>> From: Sourav Poddar >>> Date: Wed, 13 Mar 2013 20:32:36 +0530 >>> Subject: [RFC/PATCH] arm: mach-omap2: prevent UART console idle on suspend while using "no_console_suspend" >>> >>> With dt boot on omap5, uart wakeup after suspend is non functional while using >>> "no_console_suspend" in the bootargs. With "no_console_suspend" used, od->flags >>> should be ORed with "OMAP_DEVICE_NO_IDLE_ON_SUSPEND", thereby not allowing the console >>> to idle in the suspend path. For non-dt case, this was taken care by platform data. >>> >>> Tested on omap5430evm, omap4430sdp. >>> >>> Signed-off-by: Sourav Poddar >>> --- >>> The problem is I need to use couple of "extern variables" which >>> can be used in the omap_device file, after the device is built from dt. >>> >>> arch/arm/mach-omap2/omap_device.c | 7 ++++++- >>> arch/arm/mach-omap2/serial.c | 4 +++- >>> 2 files changed, 9 insertions(+), 2 deletions(-) >>> >>> diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c >>> index e065daa..f4ebf9f 100644 >>> --- a/arch/arm/mach-omap2/omap_device.c >>> +++ b/arch/arm/mach-omap2/omap_device.c >>> @@ -96,6 +96,9 @@ >>> #define USE_WAKEUP_LAT 0 >>> #define IGNORE_WAKEUP_LAT 1 >>> >>> +extern u8 no_console_suspend; >>> +extern char console_uart_name[]; >>> + >>> static int omap_early_device_register(struct platform_device *pdev); >>> >>> static struct omap_device_pm_latency omap_default_latency[] = { >>> @@ -372,7 +375,9 @@ static int omap_device_build_from_dt(struct platform_device *pdev) >>> r->name = dev_name(&pdev->dev); >>> } >>> >>> - if (of_get_property(node, "ti,no_idle_on_suspend", NULL)) >>> + if (no_console_suspend&& !strcmp(oh->name, console_uart_name)) >>> + omap_device_disable_idle_on_suspend(pdev); >>> + else if (of_get_property(node, "ti,no_idle_on_suspend", NULL)) >>> omap_device_disable_idle_on_suspend(pdev); >> Why do not use some flags instead of external variable? >> >> > That flag also need to be set in serial.c and used in omap_device.c. > Moreover, I am doing a strcmp so I need a console uart name to be passed > from serial.c to omap_device.c Just an idea, I didn't check the code if (oh->flags & OMAP_FORCE_DISABLE_IDLE_ON_SUSPEND || of_get_property(node, "ti,no_idle_on_suspend", NULL)) omap_device_disable_idle_on_suspend(pdev); And I don't know if you can set such flags in serial.c Michael >>> pdev->dev.pm_domain =&omap_device_pm_domain; >>> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c >>> index 037e691..f841ab5 100644 >>> --- a/arch/arm/mach-omap2/serial.c >>> +++ b/arch/arm/mach-omap2/serial.c >>> @@ -63,8 +63,9 @@ struct omap_uart_state { >>> static LIST_HEAD(uart_list); >>> static u8 num_uarts; >>> static u8 console_uart_id = -1; >>> -static u8 no_console_suspend; >>> static u8 uart_debug; >>> +u8 no_console_suspend; >>> +char console_uart_name[MAX_UART_HWMOD_NAME_LEN]; >>> >>> #define DEFAULT_RXDMA_POLLRATE 1 /* RX DMA polling rate (us) */ >>> #define DEFAULT_RXDMA_BUFSIZE 4096 /* RX DMA buffer size */ >>> @@ -199,6 +200,7 @@ static int __init omap_serial_early_init(void) >>> "%s%d", OMAP_SERIAL_NAME, uart->num); >>> >>> if (cmdline_find_option(uart_name)) { >>> + strcpy(console_uart_name, oh_name); >>> console_uart_id = uart->num; >>> >>> if (console_loglevel>= 10) { >> Michael > ~Sourav -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/