Re: [PATCH] OMAP3: SR: Wait for VP idle before a VP disable

[Kevin Hilman <khilman@deeprootsystems.com>]

Rajendra Nayak <rnayak@ti.com> writes:

> In the SR disable path it is recommended to wait
> for Voltage processor to idle before disabling the
> VP.
>
> Signed-off-by: Rajendra Nayak <rnayak@ti.com>

Thanks, pushing to PM branch, and pm-2.6.29 (compile tested only for .29)

Kevin

> ---
>  arch/arm/mach-omap2/smartreflex.c |   47 +++++++++++++++++++++++++++++++++++++
>  1 files changed, 47 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-omap2/smartreflex.c
> index 9d462e3..1407783 100644
> --- a/arch/arm/mach-omap2/smartreflex.c
> +++ b/arch/arm/mach-omap2/smartreflex.c
> @@ -36,6 +36,8 @@
>  #include "smartreflex.h"
>  #include "prm-regbits-34xx.h"
>  
> +#define MAX_TRIES 100
> +
>  struct omap_sr {
>  	int		srid;
>  	int		is_sr_reset;
> @@ -620,16 +622,39 @@ static int sr_enable(struct omap_sr *sr, u32 target_opp_no)
>  
>  static void sr_disable(struct omap_sr *sr)
>  {
> +	u32 i = 0;
> +
>  	sr->is_sr_reset = 1;
>  
>  	/* SRCONFIG - disable SR */
>  	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, ~SRCONFIG_SRENABLE);
>  
>  	if (sr->srid == SR1) {
> +		/* Wait for VP idle before disabling VP */
> +		while ((!prm_read_mod_reg(OMAP3430_GR_MOD,
> +					OMAP3_PRM_VP1_STATUS_OFFSET))
> +					&& i++ < MAX_TRIES)
> +			udelay(1);
> +
> +		if (i >= MAX_TRIES)
> +			pr_warning("VP1 not idle, still going ahead with \
> +							VP1 disable\n");
> +
>  		/* Disable VP1 */
>  		prm_clear_mod_reg_bits(PRM_VP1_CONFIG_VPENABLE, OMAP3430_GR_MOD,
>  					OMAP3_PRM_VP1_CONFIG_OFFSET);
> +
>  	} else if (sr->srid == SR2) {
> +		/* Wait for VP idle before disabling VP */
> +		while ((!prm_read_mod_reg(OMAP3430_GR_MOD,
> +					OMAP3_PRM_VP2_STATUS_OFFSET))
> +					&& i++ < MAX_TRIES)
> +			udelay(1);
> +
> +		if (i >= MAX_TRIES)
> +			pr_warning("VP2 not idle, still going ahead with \
> +							 VP2 disable\n");
> +
>  		/* Disable VP2 */
>  		prm_clear_mod_reg_bits(PRM_VP2_CONFIG_VPENABLE, OMAP3430_GR_MOD,
>  					OMAP3_PRM_VP2_CONFIG_OFFSET);
> @@ -731,6 +756,8 @@ void enable_smartreflex(int srid)
>  
>  void disable_smartreflex(int srid)
>  {
> +	u32 i = 0;
> +
>  	struct omap_sr *sr = NULL;
>  
>  	if (srid == SR1)
> @@ -751,11 +778,31 @@ void disable_smartreflex(int srid)
>  			/* Disable SR clk */
>  			sr_clk_disable(sr);
>  			if (sr->srid == SR1) {
> +				/* Wait for VP idle before disabling VP */
> +				while ((!prm_read_mod_reg(OMAP3430_GR_MOD,
> +						OMAP3_PRM_VP1_STATUS_OFFSET))
> +						&& i++ < MAX_TRIES)
> +					udelay(1);
> +
> +				if (i >= MAX_TRIES)
> +					pr_warning("VP1 not idle, still going \
> +						ahead with VP1 disable\n");
> +
>  				/* Disable VP1 */
>  				prm_clear_mod_reg_bits(PRM_VP1_CONFIG_VPENABLE,
>  						OMAP3430_GR_MOD,
>  						OMAP3_PRM_VP1_CONFIG_OFFSET);
>  			} else if (sr->srid == SR2) {
> +				/* Wait for VP idle before disabling VP */
> +				while ((!prm_read_mod_reg(OMAP3430_GR_MOD,
> +						OMAP3_PRM_VP2_STATUS_OFFSET))
> +						&& i++ < MAX_TRIES)
> +					udelay(1);
> +
> +				if (i >= MAX_TRIES)
> +					pr_warning("VP2 not idle, still going \
> +						 ahead with VP2 disable\n");
> +
>  				/* Disable VP2 */
>  				prm_clear_mod_reg_bits(PRM_VP2_CONFIG_VPENABLE,
>  						OMAP3430_GR_MOD,
> -- 
> 1.5.4.7
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html