Messages in this thread Patch in this message | | | Date | Fri, 5 Apr 2013 12:38:38 +0530 | From | Sourav Poddar <> | Subject | Re: [PATCH/Resend 2/2] arm: mach-omap2: prevent UART console idle on suspend while using "no_console_suspend" |
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Hi Kevin, On Wednesday 03 April 2013 11:18 PM, Kevin Hilman wrote: > Sourav Poddar<sourav.poddar@ti.com> 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<sourav.poddar@ti.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@ti.com> >>>>>> Cc: Felipe Balbi<balbi@ti.com> >>>>>> Cc: Rajendra nayak<rnayak@ti.com> >>>>>> Signed-off-by: Sourav Poddar<sourav.poddar@ti.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? >> 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 <sourav.poddar@ti.com> 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 <sourav.poddar@ti.com> --- 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 <linux/pinctrl/consumer.h> #include <linux/platform_data/serial-omap.h>
+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
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