From: "Mark A. Greer" <[email protected]> The am35x family of SoCs has a Davinci EMAC ethernet controller on-chip. Unfortunately, the EMAC is unable to wake the PRCM when there is network activity which leads to a hung or extremely slow system when the MPU has executed a 'wfi' instruction (because of pm_idle or CPUidle). To prevent this, add hooks to the EMAC pm_runtime suspend/resume calls so that hlt is disabled whenever the EMAC is in use.
Signed-off-by: Mark A. Greer <[email protected]> --- arch/arm/mach-omap2/am35xx-emac.c | 40 +++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-omap2/am35xx-emac.c b/arch/arm/mach-omap2/am35xx-emac.c index 3bb5cb3..887a057 100644 --- a/arch/arm/mach-omap2/am35xx-emac.c +++ b/arch/arm/mach-omap2/am35xx-emac.c @@ -23,6 +23,35 @@ #include "control.h" #include "am35xx-emac.h" +/* + * Default pm_lats for the am35x. + * The net effect of using am35xx_emac_pm_lats[] is that + * pm_idle or CPUidle won't be called while the emac + * interface is open. This is required because the + * EMAC can't wake up PRCM so if the MPU is executing + * a 'wfi' instruction (e.g., from pm_idle or CPUidle), + * it won't break out of it due to emac activity. + */ +static int am35xx_emac_deactivate_func(struct omap_device *od) +{ + enable_hlt(); + return omap_device_idle_hwmods(od); +} + +static int am35xx_emac_activate_func(struct omap_device *od) +{ + disable_hlt(); + return omap_device_enable_hwmods(od); +} + +static struct omap_device_pm_latency am35xx_emac_pm_lats[] = { + { + .deactivate_func = am35xx_emac_deactivate_func, + .activate_func = am35xx_emac_activate_func, + .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST, + }, +}; + static void am35xx_enable_emac_int(void) { u32 regval; @@ -61,12 +90,13 @@ static struct emac_platform_data am35xx_emac_pdata = { static struct mdio_platform_data am35xx_mdio_pdata; static int __init omap_davinci_emac_dev_init(struct omap_hwmod *oh, - void *pdata, int pdata_len) + void *pdata, int pdata_len, + struct omap_device_pm_latency *pm_lats, int pm_lats_size) { struct platform_device *pdev; pdev = omap_device_build(oh->class->name, 0, oh, pdata, pdata_len, - NULL, 0, false); + pm_lats, pm_lats_size, false); if (IS_ERR(pdev)) { WARN(1, "Can't build omap_device for %s:%s.\n", oh->class->name, oh->name); @@ -91,7 +121,7 @@ void __init am35xx_emac_init(unsigned long mdio_bus_freq, u8 rmii_en) am35xx_mdio_pdata.bus_freq = mdio_bus_freq; ret = omap_davinci_emac_dev_init(oh, &am35xx_mdio_pdata, - sizeof(am35xx_mdio_pdata)); + sizeof(am35xx_mdio_pdata), NULL, 0); if (ret) { pr_err("Could not build davinci_mdio hwmod device\n"); return; @@ -106,7 +136,9 @@ void __init am35xx_emac_init(unsigned long mdio_bus_freq, u8 rmii_en) am35xx_emac_pdata.rmii_en = rmii_en; ret = omap_davinci_emac_dev_init(oh, &am35xx_emac_pdata, - sizeof(am35xx_emac_pdata)); + sizeof(am35xx_emac_pdata), + am35xx_emac_pm_lats, + ARRAY_SIZE(am35xx_emac_pm_lats)); if (ret) { pr_err("Could not build davinci_emac hwmod device\n"); return; -- 1.7.9.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
