On 08/02/2013 12:16 AM, Stephen Warren wrote: > On 07/31/2013 11:42 AM, Tuomas Tynkkynen wrote: >> The Tegra30 TRM recommends configuration of certain PHY parameters for >> optimal quality. Program the following registers based on device tree >> parameters: >> >> - UTMIP_XCVR_HSSLEW: HS slew rate control. >> - UTMIP_HSSQUELCH_LEVEL: HS squelch detector level >> - UTMIP_HSDISCON_LEVEL: HS disconnect detector level. >> >> These registers exist in Tegra20, but programming them hasn't been >> necessary, so these parameters won't be set on Tegra20 to keep the >> device trees backward compatible. >> >> Additionally, the UTMIP_XCVR_SETUP parameter can be set from fuses >> instead of a software-programmed value, as the optimal value can >> vary between invidual boards. The boolean property >> nvidia,xcvr-setup-use-fuses can be used to enable this behaviour. > >> diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c > Those two chunks end up clearing some fields in the register now even on > earlier chips, whereas before their values were maintained when doing > the read/modify/write. Yet, the commit description says the new fields > aren't changed on Tegra20. Do the changes above need to be guarded by if > (requires_extra_tuning_parameters)? Oops, you are right. I overlooked that some of those fields have non-zero reset values. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
