Hi,
I just tried to find the source of the problem with PM-20081106 branch.
Am trying to debug this issue now.
I tried to do a check to find which commit caused the problem.
I find that it is something to do with uart pm support.
The patch commit 1e274e917472dba6c216b67c3afb3e7abe6e77e4
OMAP3: PM: Allow UARTs to be unclocked when inactive
introduces this issue.
Regards,
sriram
On Wed, Nov 12, 2008 at 7:10 PM, Sriram V <vshrirama@xxxxxxxxx> wrote:
> Hi jouni,
> I have disabled all the drivers except i2c and network also.
> i have applied your patch and still seeing problems.
>
> doing a echo mem > /sys/power/state makes the system to hang.
>
> does this work for you?
>
>
> Regards,
> sriram
>
>
> On Wed, Nov 12, 2008 at 7:05 PM, Högander Jouni
> <jouni.hogander@xxxxxxxxx> wrote:
>> "ext Sriram V" <vshrirama@xxxxxxxxx> writes:
>>
>>> Hi jouni,
>>> Does the branch "PM-20081106" work for you?
>>>
>>> When i try to do a "echo mem > /sys/power/state" on omap3evm.
>>>
>>> the system hangs. Does Suspend-Resume work on this branch?
>>
>> Yes, but you need to apply this patch (or something similiar). Have
>> you done it and still seeing problems?
>>
>>>
>>>
>>> [root@OMAP3EVM /proc]# echo mem > /sys/power/state
>>> <6>PM: Syncing filesystems ... PM: Syncing filesystems ... done.
>>> done.
>>> Freezing user space processes ... Freezing user space processes ...
>>> (elapsed 0.00 seconds) (elapsed 0.00 seconds) done.
>>> done.
>>> Freezing remaining freezable tasks ... Freezing remaining freezable
>>> tasks ... (elapsed 0.00 seconds) (elapsed 0.00 seconds) done.done.
>>>
>>> Suspending console(s) (use no_console_suspend to debug)
>>> Suspending console(s) (use no_console_suspend to debug)
>>>
>>> ---- system hangs----
>>>
>>>
>>> With Regards,
>>> Sriram
>>>
>>>
>>>
>>> On Wed, Nov 12, 2008 at 6:43 PM, Högander Jouni
>>> <jouni.hogander@xxxxxxxxx> wrote:
>>>> "ext Jouni Hogander" <jouni.hogander@xxxxxxxxx> writes:
>>>>
>>>>> Current implementation makes it possible that printouts are
>>>>> written into UART while its clocks are disabled. This causes freeze.
>>>>
>>>> Now I got how this new uart clock handling works. Event thought this
>>>> fix is not too sensible it actually does what is needed.
>>>>
>>>> So the problem is that uart clocks are enabled in prcm_interrupt. Now
>>>> if some other interrupt handler is run before prcm_interrupt_handler
>>>> and it tries to printout something to uart -> system freezes.
>>>>
>>>> Kevin, you should ensure some way that uart clocks are enabled right
>>>> away after wakeup. This patch presents one possibile
>>>> implementation. Another way could be to move uart_check_wakeup to be
>>>> run in idle loop rather than in interrupt handler.
>>>>
>>>>>
>>>>> This patch contains possible fix for this.
>>>>>
>>>>> Signed-off-by: Jouni Hogander <jouni.hogander@xxxxxxxxx>
>>>>> ---
>>>>> arch/arm/mach-omap2/pm34xx.c | 6 ++++++
>>>>> arch/arm/mach-omap2/serial.c | 30 ++++++++++++++++++++++++++++++
>>>>> arch/arm/plat-omap/include/mach/serial.h | 2 ++
>>>>> 3 files changed, 38 insertions(+), 0 deletions(-)
>>>>>
>>>>> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
>>>>> index d480c39..3838a19 100644
>>>>> --- a/arch/arm/mach-omap2/pm34xx.c
>>>>> +++ b/arch/arm/mach-omap2/pm34xx.c
>>>>> @@ -320,6 +320,7 @@ void omap_sram_idle(void)
>>>>> /* PER */
>>>>> per_next_state = pwrdm_read_next_pwrst(per_pwrdm);
>>>>> if (per_next_state < PWRDM_POWER_ON) {
>>>>> + omap_uart_prepare_idle(2);
>>>>> omap2_gpio_prepare_for_retention();
>>>>> if (per_next_state == PWRDM_POWER_OFF)
>>>>> omap3_per_save_context();
>>>>> @@ -328,6 +329,8 @@ void omap_sram_idle(void)
>>>>> /* CORE */
>>>>> core_next_state = pwrdm_read_next_pwrst(core_pwrdm);
>>>>> if (core_next_state < PWRDM_POWER_ON) {
>>>>> + omap_uart_prepare_idle(0);
>>>>> + omap_uart_prepare_idle(1);
>>>>> if (core_next_state == PWRDM_POWER_OFF) {
>>>>> prm_set_mod_reg_bits(OMAP3430_AUTO_OFF,
>>>>> OMAP3430_GR_MOD,
>>>>> @@ -386,6 +389,8 @@ void omap_sram_idle(void)
>>>>> prm_clear_mod_reg_bits(OMAP3430_AUTO_OFF,
>>>>> OMAP3430_GR_MOD,
>>>>> OMAP3_PRM_VOLTCTRL_OFFSET);
>>>>> + omap_uart_resume_idle(0);
>>>>> + omap_uart_resume_idle(1);
>>>>> }
>>>>>
>>>>> /* PER */
>>>>> @@ -394,6 +399,7 @@ void omap_sram_idle(void)
>>>>> if (per_prev_state == PWRDM_POWER_OFF)
>>>>> omap3_per_restore_context();
>>>>> omap2_gpio_resume_after_retention();
>>>>> + omap_uart_resume_idle(2);
>>>>> }
>>>>>
>>>>> /* Enable smartreflex after WFI */
>>>>> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
>>>>> index 65cce87..ef30d8d 100644
>>>>> --- a/arch/arm/mach-omap2/serial.c
>>>>> +++ b/arch/arm/mach-omap2/serial.c
>>>>> @@ -249,6 +249,36 @@ static void omap_uart_idle_timer(unsigned long data)
>>>>> omap_uart_allow_sleep(uart);
>>>>> }
>>>>>
>>>>> +void omap_uart_prepare_idle(int num)
>>>>> +{
>>>>> + struct omap_uart_state *uart;
>>>>> +
>>>>> + if (!clocks_off_while_idle)
>>>>> + return;
>>>>> +
>>>>> + list_for_each_entry(uart, &uart_list, node) {
>>>>> + if (num == uart->num && uart->can_sleep) {
>>>>> + omap_uart_disable_clocks(uart);
>>>>> + return;
>>>>> + }
>>>>> + }
>>>>> +}
>>>>> +
>>>>> +void omap_uart_resume_idle(int num)
>>>>> +{
>>>>> + struct omap_uart_state *uart;
>>>>> +
>>>>> + if (!clocks_off_while_idle)
>>>>> + return;
>>>>> +
>>>>> + list_for_each_entry(uart, &uart_list, node) {
>>>>> + if (num == uart->num) {
>>>>> + omap_uart_enable_clocks(uart);
>>>>> + return;
>>>>> + }
>>>>> + }
>>>>> +}
>>>>> +
>>>>> void omap_uart_check_wakeup(void)
>>>>> {
>>>>> struct omap_uart_state *uart;
>>>>> diff --git a/arch/arm/plat-omap/include/mach/serial.h b/arch/arm/plat-omap/include/mach/serial.h
>>>>> index 11ff540..254a775 100644
>>>>> --- a/arch/arm/plat-omap/include/mach/serial.h
>>>>> +++ b/arch/arm/plat-omap/include/mach/serial.h
>>>>> @@ -44,6 +44,8 @@
>>>>> extern void omap_serial_init(void);
>>>>> extern int omap_uart_can_sleep(void);
>>>>> extern void omap_uart_check_wakeup(void);
>>>>> +extern void omap_uart_prepare_idle(int num);
>>>>> +extern void omap_uart_resume_idle(int num);
>>>>> #endif
>>>>>
>>>>> #endif
>>>>> --
>>>>> 1.6.0.1
>>>>>
>>>>> --
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>>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
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>>>>
>>>> --
>>>> Jouni Högander
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>>
>>
>> --
>> Jouni Högander
>>
>>
>
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