Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161731Ab3DEHI5 (ORCPT ); Fri, 5 Apr 2013 03:08:57 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:35684 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751111Ab3DEHIz (ORCPT ); Fri, 5 Apr 2013 03:08:55 -0400 Message-ID: <515E7876.3080407@ti.com> Date: Fri, 5 Apr 2013 12:38:38 +0530 From: Sourav Poddar User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.28) Gecko/20120313 Thunderbird/3.1.20 MIME-Version: 1.0 To: Kevin Hilman CC: Santosh Shilimkar , Felipe Balbi , Rajendra nayak , , , , LKML , 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> <87txnnzesd.fsf@linaro.org> In-Reply-To: <87txnnzesd.fsf@linaro.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7003 Lines: 196 Hi Kevin, On Wednesday 03 April 2013 11:18 PM, Kevin Hilman wrote: > Sourav Poddar writes: > >> 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. > As I explained earlier, any device specific hacks inside omap_device > should be a red flag that something has gone wrong. > > How about fixing the UART driver/core to not runtime suspend if > no_console_suspend is given? > > Then we can get rid of this no_idle_on_suspend hack all together since > UART is the only remaining user. > Yes, that can be done. I cooked up an experimental patch, based on your above suggestion. The patch is inlined along with the mail. I tested the patch and it resolves the issue. Depending on whether no_console_suspend is used or not, we can set a variable which can be used as a condition in runtime api's in serial driver. The information whether "no_console_suspend" is used or not is parsed in serial.c file, and this need to be communicated to the driver layer. In my experimental patch below, I have used an extern variable "force_console_suspend_disable". Do you see a better way of handling this without using extern? --------- From: Sourav Poddar Date: Wed, 13 Mar 2013 20:32:36 +0530 Subject: [PATCH] arm: mach-omap2: prevent UART console idle on suspend while using "no_console_suspend" With dt boot, 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. Tested on omap5430evm, omap4430sdp. Signed-off-by: Sourav Poddar --- arch/arm/mach-omap2/serial.c | 6 ++++-- drivers/tty/serial/omap-serial.c | 6 +++++- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c index f660156..427c407 100644 --- a/arch/arm/mach-omap2/serial.c +++ b/arch/arm/mach-omap2/serial.c @@ -51,7 +51,7 @@ #define DEFAULT_AUTOSUSPEND_DELAY -1 #define MAX_UART_HWMOD_NAME_LEN 16 - +int force_console_suspend_disable; struct omap_uart_state { int num; @@ -207,8 +207,10 @@ static int __init omap_serial_early_init(void) uart_name, uart->num); } - if (cmdline_find_option("no_console_suspend")) + if (cmdline_find_option("no_console_suspend")) { + force_console_suspend_disable = 1; no_console_suspend = true; + } /* * omap-uart can be used for earlyprintk logs diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 08332f3..395ade8 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -43,6 +43,7 @@ #include #include +extern int force_console_suspend_disable; #define OMAP_MAX_HSUART_PORTS 6 #define UART_BUILD_REVISION(x, y) (((x) << 8) | (y)) @@ -1582,7 +1583,7 @@ static int serial_omap_runtime_suspend(struct device *dev) struct uart_omap_port *up = dev_get_drvdata(dev); struct omap_uart_port_info *pdata = dev->platform_data; - if (!up) + if (!up || force_console_suspend_disable) return -EINVAL; if (!pdata) @@ -1614,6 +1615,9 @@ static int serial_omap_runtime_resume(struct device *dev) int loss_cnt = serial_omap_get_context_loss_count(up); + if (force_console_suspend_disable) + return -EINVAL; + if (loss_cnt < 0) { dev_err(dev, "serial_omap_get_context_loss_count failed : %d\n", loss_cnt); -- 1.7.1 -- 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/