On Wed, Dec 03, 2025 at 04:51:20PM +0530, Balaji Selvanathan wrote: > > On 11/26/2025 7:54 PM, Casey Connolly wrote: > > Hi Balaji, > > > > On 24/11/2025 16:55, Balaji Selvanathan wrote: > > > Add CONFIG_QCOM_USB_FIXUP option to allow platforms to disable > > > the USB speed limitation fixup when they have proper super-speed > > > USB support in U-Boot. > > In general, we prefer to handle cases like this at runtime rather than > > compile time. Could you rework this to check for the "qcom,sc7280-dwc3" > > compatible and just skip the check in that case? I would also propose > > adding a log_warning() in the fixup case so that folks working on other > > platforms know to add their compatible too. > > > > Obviously that's still not an ideal solution, maybe it would be possible > > to implement the Super Smart (tm) fix and actually check if a driver > > /will/ bind to the ss-phy node before the fixup, it depends how slow > > that would be. > This is good idea. Actually, I have implemented the super smart fix rather > than hardcoding > > "qcom,sc7280-dwc3" in code. The respined code is here: > https://lore.kernel.org/u-boot/[email protected]/; > The code checks if the SS PHY driver is indeed available and if it exists, > then it skips doing > USB HS fixup. > The entire time to check if the SS PHY driver is available is ~125ms. Request > to say if this is reasonable.
I don't think it's reasonable to add more than 125ms in boot for every platform considering slower platforms as compared to RB3G2 where it will be much worse. Lets just rather add a static check for "qcom,sc7280-dwc3" to skip the USB fixup. -Sumit > The power domain fixup is taking ~98us (mentioning just for comparison). > Thanks, > Balaji > > > > > Kind regards, > > > > > Currently, U-Boot limits USB to high-speed mode on all Qualcomm > > > platforms by fixing up the device tree at runtime. This was > > > necessary because most platforms lacked super-speed PHY drivers. > > > > > > However, newer platforms now have proper QMP PHY drivers that support > > > super-speed USB. For these platforms, the fixup is counterproductive > > > as it prevents the hardware from operating at its full capability. > > > > > > This change: > > > - Adds CONFIG_QCOM_USB_FIXUP (default y) to maintain backward > > > compatibility with existing platforms > > > - Wraps the fixup code with #ifdef to allow selective disabling > > > - Allows platforms with super-speed support to disable the fixup > > > via their defconfig > > > > > > Platforms without super-speed PHY drivers will continue to work > > > as before with the fixup enabled by default. > > > > > > Signed-off-by: Balaji Selvanathan <[email protected]> > > > --- > > > arch/arm/mach-snapdragon/Kconfig | 10 ++++++++++ > > > arch/arm/mach-snapdragon/of_fixup.c | 4 ++++ > > > 2 files changed, 14 insertions(+) > > > > > > diff --git a/arch/arm/mach-snapdragon/Kconfig > > > b/arch/arm/mach-snapdragon/Kconfig > > > index 976c0e35fce..6c53aeef597 100644 > > > --- a/arch/arm/mach-snapdragon/Kconfig > > > +++ b/arch/arm/mach-snapdragon/Kconfig > > > @@ -29,6 +29,16 @@ config SYS_MALLOC_LEN > > > config LNX_KRNL_IMG_TEXT_OFFSET_BASE > > > default 0x80000000 > > > +config QCOM_USB_FIXUP > > > + bool "Enable USB speed fixup for Qualcomm platforms" > > > + default y > > > + help > > > + Enable runtime fixup of USB device tree nodes to limit USB to > > > + high-speed mode. This is needed on some Qualcomm platforms where > > > + U-Boot doesn't support super-speed USB. > > > + Disable this for platforms that have proper super-speed USB support > > > + in U-Boot. > > > + > > > config SYS_BOARD > > > string "Snapdragon SoCs based board" > > > help > > > diff --git a/arch/arm/mach-snapdragon/of_fixup.c > > > b/arch/arm/mach-snapdragon/of_fixup.c > > > index eec2c0c757e..6a64168f67e 100644 > > > --- a/arch/arm/mach-snapdragon/of_fixup.c > > > +++ b/arch/arm/mach-snapdragon/of_fixup.c > > > @@ -27,6 +27,7 @@ > > > #include <stdlib.h> > > > #include <time.h> > > > +#ifdef CONFIG_QCOM_USB_FIXUP > > > /* U-Boot only supports USB high-speed mode on Qualcomm platforms with > > > DWC3 > > > * USB controllers. Rather than requiring source level DT changes, we > > > fix up > > > * DT here. This improves compatibility with upstream DT and simplifies > > > the > > > @@ -115,6 +116,7 @@ static void fixup_usb_nodes(struct device_node *root) > > > log_warning("Failed to fixup node %s: %d\n", > > > glue_np->name, ret); > > > } > > > } > > > +#endif > > > /* Remove all references to the rpmhpd device */ > > > static void fixup_power_domains(struct device_node *root) > > > @@ -157,7 +159,9 @@ static int qcom_of_fixup_nodes(void * __maybe_unused > > > ctx, struct event *event) > > > { > > > struct device_node *root = event->data.of_live_built.root; > > > +#ifdef CONFIG_QCOM_USB_FIXUP > > > time_call(fixup_usb_nodes, root); > > > +#endif > > > time_call(fixup_power_domains, root); > > > return 0;
