On Wed, Sep 21, 2022 at 03:54:13PM +0200, Pali Rohár wrote: > On Wednesday 21 September 2022 09:49:24 Tom Rini wrote: > > On Mon, Sep 05, 2022 at 11:31:15AM +0200, Pali Rohár wrote: > > > > > On certain places it is required to flush output print buffers to ensure > > > that text strings were sent to console or serial devices. For example when > > > printing message that U-Boot is going to boot kernel or when U-Boot is > > > going to change baudrate of terminal device. > > > > > > Some console devices, like UART, have putc/puts functions which just put > > > characters into HW transmit queue and do not wait until all data are > > > transmitted. Doing some sensitive operations (like changing baudrate or > > > starting kernel which resets UART HW) cause that U-Boot messages are lost. > > > > > > Therefore introduce a new flush() function, implement it for all serial > > > devices via pending(false) callback and use this new flush() function on > > > sensitive places after which output device may go into reset state. > > > > > > This change fixes printing of U-Boot messages: > > > "## Starting application at ..." > > > "## Switch baudrate to ..." > > > > > > Changes in v3: > > > * add macro STDIO_DEV_ASSIGN_FLUSH() > > > * fix commit messages > > > * remove changes from serial.c > > > > > > Changes in v2: > > > * split one big patch into smaller 6 patches > > > * add config option to allow disabling this new function > > > > > > Pali Rohár (6): > > > sandbox: Add function os_flush() > > > console: Implement flush() function > > > serial: Implement flush callback > > > serial: Implement serial_flush() function for console flush() fallback > > > serial: Call flush() before changing baudrate > > > boot: Call flush() before booting > > > > Including the change you suggested to 4/6 to fix that build issue, > > there's at least one more large issue that prevents CI from getting too > > far: > > https://source.denx.de/u-boot/u-boot/-/pipelines/13534 > > and they all have a failure similar to: > > https://source.denx.de/u-boot/u-boot/-/jobs/500794#L51 > > It looks like that some efi stuff overloads u-boot functions, in this > case newly added flush() function. > > Any idea how to handle this issue? > > The only option which I see how to address it is to revert those changes > in source files which always calls flush() function and replace them by > my first attempt which use guard #ifdef to ensure that flush() call is > completely eliminated at preprocessor stage when efi is enabled.
Adding in Heinrich. -- Tom
signature.asc
Description: PGP signature
