"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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>>
>> --
>> 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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