On Mon, 19 Sept 2022 at 05:28, Michael Ellerman <m...@ellerman.id.au> wrote: > > The original microwatt submission[1] included some early debug code for > using the Microwatt "potato" UART.
The potato is indeed dead. > > The series that was eventually merged switched to using a standard UART, > and so doesn't need any special early debug handling. But some of the > original code was merged accidentally under the non-existent > CONFIG_PPC_EARLY_DEBUG_MICROWATT. The kconfig never got added, so you're right. Using the "legacy serial console" must be how we get early console on microwatt? I can't quite work it out. May or may not be related to https://github.com/linuxppc/issues/issues/413 > > Drop the unused code. > > 1: > https://lore.kernel.org/linuxppc-dev/20200509050340.gd1464...@thinks.paulus.ozlabs.org/ > > Fixes: 48b545b8018d ("powerpc/microwatt: Use standard 16550 UART for console") > Reported-by: Lukas Bulwahn <lukas.bulw...@gmail.com> > Signed-off-by: Michael Ellerman <m...@ellerman.id.au> > --- > arch/powerpc/kernel/udbg_16550.c | 39 -------------------------------- > 1 file changed, 39 deletions(-) > > diff --git a/arch/powerpc/kernel/udbg_16550.c > b/arch/powerpc/kernel/udbg_16550.c > index d3942de254c6..ddfbc74bf85f 100644 > --- a/arch/powerpc/kernel/udbg_16550.c > +++ b/arch/powerpc/kernel/udbg_16550.c > @@ -296,42 +296,3 @@ void __init udbg_init_40x_realmode(void) > } > > #endif /* CONFIG_PPC_EARLY_DEBUG_40x */ > - > -#ifdef CONFIG_PPC_EARLY_DEBUG_MICROWATT > - > -#define UDBG_UART_MW_ADDR ((void __iomem *)0xc0002000) > - > -static u8 udbg_uart_in_isa300_rm(unsigned int reg) > -{ > - uint64_t msr = mfmsr(); > - uint8_t c; > - > - mtmsr(msr & ~(MSR_EE|MSR_DR)); > - isync(); > - eieio(); > - c = __raw_rm_readb(UDBG_UART_MW_ADDR + (reg << 2)); > - mtmsr(msr); > - isync(); > - return c; > -} > - > -static void udbg_uart_out_isa300_rm(unsigned int reg, u8 val) > -{ > - uint64_t msr = mfmsr(); > - > - mtmsr(msr & ~(MSR_EE|MSR_DR)); > - isync(); > - eieio(); > - __raw_rm_writeb(val, UDBG_UART_MW_ADDR + (reg << 2)); > - mtmsr(msr); > - isync(); > -} > - > -void __init udbg_init_debug_microwatt(void) > -{ > - udbg_uart_in = udbg_uart_in_isa300_rm; > - udbg_uart_out = udbg_uart_out_isa300_rm; > - udbg_use_uart(); > -} > - > -#endif /* CONFIG_PPC_EARLY_DEBUG_MICROWATT */ > -- > 2.37.2 >