Hi Simon, Thank you for your patch.
On ven., sept. 22, 2023 at 15:38, Simon Glass <s...@chromium.org> wrote: > When a USB device is unbound, it causes any bootflows attached to it to > be removed, via a call to bootdev_clear_bootflows() from > bootdev_pre_unbind(). This obviously makes it impossible to boot the > bootflow. > > However, when booting a bootflow that relies on USB, usb_stop() is > called, which unbinds the device. For EFI, this happens in > efi_exit_boot_services() which means that the bootflow disappears > before it is finished with. > > There is no need to unbind all the USB devices just to quiesce them. > Add a new usb_pause() call which removes them but leaves them bound. > > This resolves a hang on x86 when booting a distro from USB. This was > found using a device with 4 bootflows, the last of which was USB. > > Signed-off-by: Simon Glass <s...@chromium.org> > --- > > Changes in v2: > - Add new patch to avoid unbinding devices in use by bootflows > > boot/bootm.c | 2 +- > common/usb.c | 7 ++++++- > drivers/usb/host/usb-uclass.c | 14 ++++++++++++-- > include/usb.h | 15 ++++++++++++++- > 4 files changed, 33 insertions(+), 5 deletions(-) > > diff --git a/boot/bootm.c b/boot/bootm.c > index b1c3afe0a3a..5c9ba083e64 100644 > --- a/boot/bootm.c > +++ b/boot/bootm.c > @@ -501,7 +501,7 @@ ulong bootm_disable_interrupts(void) > * updated every 1 ms within the HCCA structure in SDRAM! For more > * details see the OpenHCI specification. > */ > - usb_stop(); > + usb_pause(); > #endif > return iflag; > } > diff --git a/common/usb.c b/common/usb.c > index 836506dcd9e..4d6ac69111e 100644 > --- a/common/usb.c > +++ b/common/usb.c > @@ -126,7 +126,7 @@ int usb_init(void) > > /****************************************************************************** > * Stop USB this stops the LowLevel Part and deregisters USB devices. > */ > -int usb_stop(void) > +int usb_pause(void) nit: I know this is the "legacy" (pre-DM) stuff, but isn't renaming the above function making the comment wrong? Can't we keep this function usb_stop() and create another one named usb_pause() which calls usb_stop() ? > { > int i; > > @@ -144,6 +144,11 @@ int usb_stop(void) > return 0; > } > > +int usb_stop(void) > +{ > + return usb_pause(); > +} > + > > /****************************************************************************** > * Detect if a USB device has been plugged or unplugged. > */ > diff --git a/drivers/usb/host/usb-uclass.c b/drivers/usb/host/usb-uclass.c > index a1cd0ad2d66..c26c65d7986 100644 > --- a/drivers/usb/host/usb-uclass.c > +++ b/drivers/usb/host/usb-uclass.c > @@ -173,7 +173,7 @@ int usb_get_max_xfer_size(struct usb_device *udev, size_t > *size) > return ops->get_max_xfer_size(bus, size); > } > > -int usb_stop(void) > +static int usb_finish(bool unbind_all) > { > struct udevice *bus; > struct udevice *rh; > @@ -195,7 +195,7 @@ int usb_stop(void) > > /* Locate root hub device */ > device_find_first_child(bus, &rh); > - if (rh) { > + if (rh && unbind_all) { > /* > * All USB devices are children of root hub. > * Unbinding root hub will unbind all of its children. > @@ -222,6 +222,16 @@ int usb_stop(void) > return err; > } > > +int usb_stop(void) > +{ > + return usb_finish(true); > +} > + > +int usb_pause(void) > +{ > + return usb_finish(false); > +} What happens if someone calls usb_pause() followed by usb_init() on a root hub ? I think it behaves properly because usb_init() calls remove_inactive_children(). > + > static void usb_scan_bus(struct udevice *bus, bool recurse) > { > struct usb_bus_priv *priv; > diff --git a/include/usb.h b/include/usb.h > index 09e3f0cb309..ad39b09a6e4 100644 > --- a/include/usb.h > +++ b/include/usb.h > @@ -265,7 +265,20 @@ int usb_kbd_deregister(int force); > */ > int usb_init(void); > > -int usb_stop(void); /* stop the USB Controller */ > +/** > + * usb_stop() - stop the USB Controller and unbind all USB > controllers/devices > + * > + * Return: 0 if OK, -ve on error > + */ > +int usb_stop(void); > + > +/** > + * usb_pause() - stop the USB Controller DMA, etc. > + * > + * Return: 0 if OK, -ve on error > + */ > +int usb_pause(void); > + > int usb_detect_change(void); /* detect if a USB device has been (un)plugged > */ > > > -- > 2.42.0.515.g380fc7ccd1-goog