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Date: Wed, 20 Mar 2013 17:36:20 +0530
From: Sourav Poddar <sourav.poddar@...com>
To: Kevin Hilman <khilman@...aro.org>
CC: Santosh Shilimkar <santosh.shilimkar@...com>,
Felipe Balbi <balbi@...com>, Rajendra nayak <rnayak@...com>,
<tony@...mide.com>, <rmk+kernel@....linux.org.uk>,
<linux-serial@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>
Subject: Re: [PATCH/Resend 2/2] arm: mach-omap2: prevent UART console idle
on suspend while using "no_console_suspend"
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<sourav.poddar@...com> 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<santosh.shilimkar@...com>
>>> Cc: Felipe Balbi<balbi@...com>
>>> Cc: Rajendra nayak<rnayak@...com>
>>> Signed-off-by: Sourav Poddar<sourav.poddar@...com>
>> 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?
>> Kevin
>>
>>> ---
>>> arch/arm/mach-omap2/omap_device.c | 34
>>> +++++++++++++++++++++++++++++++++-
>>> 1 files changed, 33 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-omap2/omap_device.c
>>> b/arch/arm/mach-omap2/omap_device.c
>>> index 381be7a..71f5a73 100644
>>> --- a/arch/arm/mach-omap2/omap_device.c
>>> +++ b/arch/arm/mach-omap2/omap_device.c
>>> @@ -35,11 +35,17 @@
>>> #include<linux/pm_runtime.h>
>>> #include<linux/of.h>
>>> #include<linux/notifier.h>
>>> +#include<linux/platform_data/serial-omap.h>
>>>
>>> #include "soc.h"
>>> #include "omap_device.h"
>>> #include "omap_hwmod.h"
>>>
>>> +#define MAX_UART_HWMOD_NAME_LEN 16
>>> +
>>> +static u8 no_console_suspend;
>>> +static u8 console_uart_num;
>>> +
>>> /* Private functions */
>>>
>>> static void _add_clkdev(struct omap_device *od, const char
>>> *clk_alias,
>>> @@ -108,6 +114,12 @@ static void _add_hwmod_clocks_clkdev(struct
>>> omap_device *od,
>>> _add_clkdev(od, oh->opt_clks[i].role, oh->opt_clks[i].clk);
>>> }
>>>
>>> +static char *cmdline_find_option(char *str)
>>> +{
>>> + extern char *saved_command_line;
>>> +
>>> + return strstr(saved_command_line, str);
>>> +}
>>>
>>> /**
>>> * omap_device_build_from_dt - build an omap_device with multiple
>>> hwmods
>>> @@ -129,6 +141,7 @@ static int omap_device_build_from_dt(struct
>>> platform_device *pdev)
>>> struct device_node *node = pdev->dev.of_node;
>>> const char *oh_name;
>>> int oh_cnt, i, ret = 0;
>>> + static u8 console_uart_id;
>>>
>>> oh_cnt = of_property_count_strings(node, "ti,hwmods");
>>> if (!oh_cnt || IS_ERR_VALUE(oh_cnt)) {
>>> @@ -170,7 +183,12 @@ 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&& !strncmp(oh->name, "uart", 4)) {
>>> + if (console_uart_num == console_uart_id)
>>> + omap_device_disable_idle_on_suspend(pdev);
>>> + else
>>> + console_uart_id++;
>>> + } else if (of_get_property(node, "ti,no_idle_on_suspend", NULL))
>>> omap_device_disable_idle_on_suspend(pdev);
>>>
>>> pdev->dev.pm_domain =&omap_device_pm_domain;
>>> @@ -838,7 +856,21 @@ static struct notifier_block platform_nb = {
>>>
>>> static int __init omap_device_init(void)
>>> {
>>> + int i;
>>> + char uart_name[MAX_UART_HWMOD_NAME_LEN];
>>> +
>>> bus_register_notifier(&platform_bus_type,&platform_nb);
>>> +
>>> + if (cmdline_find_option("no_console_suspend")) {
>>> + no_console_suspend = true;
>>> + for (i = 0; i< OMAP_MAX_HSUART_PORTS; i++) {
>>> + snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
>>> + "%s%d", OMAP_SERIAL_NAME, i);
>>> + if (cmdline_find_option(uart_name))
>>> + console_uart_num = i;
>>> + }
>>> + }
>>> +
>>> return 0;
>>> }
>>> omap_core_initcall(omap_device_init);
>
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