Message ID | 1418406612-3243-2-git-send-email-hdegoede@redhat.com |
---|---|
State | Superseded |
Delegated to: | Hans de Goede |
Headers | show |
On 12/12/2014 10:50 AM, Hans de Goede wrote: > When using usb-keyboard support, typically usb will already get started from > preboot. In this case doing it again in the bootcmd is undesirable. > > Allow the user of config_distro_bootcmd to indicate that usb is inited in > preboot through the user setting BOOTENV_PREBOOT_INITS_USB. Sorry, I don't recall seeing this whenever it was posted before. Conceptually this seems fine. One issue it has is with the following sequence: PREBOOT inits USB, no USB drive found (not plugged in) User CTRL-Cs boot sequence User plugs in USB drive User runs "boot" or "run bootcmd" -> USB not re-detected, so system doesn't boot from USB. Perhaps the best way to solve this is to have a flag controlling whether BOOTENV_SET_USB_NEED_INIT sets $usb_need_init? preboot: setenv usb_do_set_usb_need_init false BOOTENV_SET_USB_NEED_INIT: # Normally unset -> true # In your case, preboot sets this to false if ${usb_do_set_usb_need_init}; then setenv usb_need_init else # Next time $boot is run, this will be unset -> true # so we will re-init USB setenv usb_do_set_usb_need_init # This time through, we skip USB init setenv usb_need_init false endif Of course, that doesn't solve the problem of the user aborting auto-boot before it's ever run once. Perhaps better would be a flag that BOOTENV_SET_USB_NEED_INIT can use to distinguish auto-boot and manual invocation, i.e.: preboot: setenv usb_do_set_usb_need_init false BOOTENV_SET_USB_NEED_INIT: # U-Boot C code sets this appropriatelyL if ${auto_boot}; then # Auto case: Init USB unless preboot set a flag if ${usb_do_set_usb_need_init}; then setenv usb_need_init else # Next time $boot is run, this will be unset -> true # so we will re-init USB setenv usb_do_set_usb_need_init # This time through, we skip USB init setenv usb_need_init false endif else # Manual case: Always init USB setenv usb_need_init endif Or do we just assume that if the user plugs in a new USB device after boot, they must manually run USB initialization? If so, we cam simplify the existing $usb_need_init a bit...
On 12/12/2014 Stephen Warren wrote: > On 12-12-14 10:50 AM, Hans de Goede wrote: > > When using usb-keyboard support, typically usb will already get started from > > preboot. In this case doing it again in the bootcmd is undesirable. > > > > Allow the user of config_distro_bootcmd to indicate that usb is inited in > > preboot through the user setting BOOTENV_PREBOOT_INITS_USB. > >Sorry, I don't recall seeing this whenever it was posted before. > > Conceptually this seems fine. One issue it has is with the following > sequence: > > PREBOOT inits USB, no USB drive found (not plugged in) > User CTRL-Cs boot sequence > User plugs in USB drive > User runs "boot" or "run bootcmd" > -> USB not re-detected, so system doesn't boot from USB. > > Perhaps the best way to solve this is to have a flag controlling whether > BOOTENV_SET_USB_NEED_INIT sets $usb_need_init? > > preboot: > setenv usb_do_set_usb_need_init false > > BOOTENV_SET_USB_NEED_INIT: > # Normally unset -> true > # In your case, preboot sets this to false > if ${usb_do_set_usb_need_init}; then > setenv usb_need_init > else > # Next time $boot is run, this will be unset -> true > # so we will re-init USB > setenv usb_do_set_usb_need_init > # This time through, we skip USB init > setenv usb_need_init false > endif > > Of course, that doesn't solve the problem of the user aborting auto-boot > before it's ever run once. Perhaps better would be a flag that > BOOTENV_SET_USB_NEED_INIT can use to distinguish auto-boot and manual > invocation, i.e.: > > preboot: > setenv usb_do_set_usb_need_init false > > BOOTENV_SET_USB_NEED_INIT: > # U-Boot C code sets this appropriatelyL > if ${auto_boot}; then > # Auto case: Init USB unless preboot set a flag > if ${usb_do_set_usb_need_init}; then > setenv usb_need_init > else > # Next time $boot is run, this will be unset -> true > # so we will re-init USB > setenv usb_do_set_usb_need_init > # This time through, we skip USB init > setenv usb_need_init false > endif > else > # Manual case: Always init USB > setenv usb_need_init > endif > > Or do we just assume that if the user plugs in a new USB device after > boot, they must manually run USB initialization? If so, we cam simplify > the existing $usb_need_init a bit... Looking at all the extra code (and possible bugs / problems that code may introduce), I think that it makes sense to just expect the user to run "usb reset" after plugging in a new device. Regards, Hans
diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h index be616e8..fd01a34 100644 --- a/include/config_distro_bootcmd.h +++ b/include/config_distro_bootcmd.h @@ -91,7 +91,11 @@ #ifdef CONFIG_CMD_USB #define BOOTENV_RUN_USB_INIT "run usb_init; " +#ifndef BOOTENV_PREBOOT_INITS_USB #define BOOTENV_SET_USB_NEED_INIT "setenv usb_need_init; " +#else +#define BOOTENV_SET_USB_NEED_INIT "setenv usb_need_init false; " +#endif #define BOOTENV_SHARED_USB \ "usb_init=" \ "if ${usb_need_init}; then " \
When using usb-keyboard support, typically usb will already get started from preboot. In this case doing it again in the bootcmd is undesirable. Allow the user of config_distro_bootcmd to indicate that usb is inited in preboot through the user setting BOOTENV_PREBOOT_INITS_USB. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- include/config_distro_bootcmd.h | 4 ++++ 1 file changed, 4 insertions(+)