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.
>
> This patch contains possible fix for this.
Thanks, pulling into PM branch until final solution can be found.
Kevin
> 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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