I would like to revive an old discussion regarding how to use a particular idle mode for a specific use-case[1]. As per the OMAP4 documentation, audio over HDMI should be transmitted in no-idle mode. This patch adds the HWMOD_SWSUP_SIDLE so that omap_hwmode uses no-idle/force-idle settings instead of smart-idle. However, if this flag is used, smart-idle nor smart-idle wakeup-capable features could not be used. This would not be ideal if we want, for instance, to wake up using a HDMI cable connect event. Ideally, the HDMI module should be set to no-idle when transmitting audio and then go back to whatever mode it was (e.g., smart-idle) when audio transmission is over. I am not sure how to do that, though. In the past, it was suggested to use an integration function through platform_data[2], which didn't seem to be suitable from the device tree perspective; although there were no other alternatives[3]. It was also suggested to add functions to allow/block smart-idle momentarily[4], but how would the driver let know omap_hwmod when to allow/block smart-idle without using platform_data/integration function? Thanks for your comments! Ricardo [1].http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg60226.html [2].http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg60236.html [3].http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg60316.html [4].http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg60252.html Signed-off-by: Ricardo Neri <ricardo.neri@xxxxxx> --- arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c index 950454a..3568b3b 100644 --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c @@ -865,6 +865,11 @@ static struct omap_hwmod omap44xx_dss_hdmi_hwmod = { }, .opt_clks = dss_hdmi_opt_clks, .opt_clks_cnt = ARRAY_SIZE(dss_hdmi_opt_clks), + /* + * HDMI audio requires to not rely on smart idle and + * use no-idle instead. Hence, set idle mode by software. + */ + .flags = HWMOD_SWSUP_SIDLE, }; /* -- 1.7.5.4 -- 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
