On 9/11/20 2:33 PM, Du Huanpeng wrote: > this make it possiable pass a0 as divisor to calculate uart baudrate > in run time on boot. This is not Ok. Your last commit has your board pass the divisor in a0 now, but other boards, like the netgear-wg102, don't. Your change might break their UART because the code there doesn't expect that a0 needs to have a valid value. If you want to do this, you should migrate all users of this function all at once to supply a valid divisor (probably `move a0, DEBUG_LL_UART_DIVISOR`). It's same thing in C. You don't add a new parameter to a function without checking that all callsites handle this correctly. > > Signed-off-by: Du Huanpeng <u74147@xxxxxxxxx> > --- > arch/mips/include/asm/debug_ll_ns16550.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h > index df58c4c..a33587a 100644 > --- a/arch/mips/include/asm/debug_ll_ns16550.h > +++ b/arch/mips/include/asm/debug_ll_ns16550.h > @@ -66,6 +66,9 @@ static inline void PUTC_LL(char ch) > sb t1, UART_LCR(t0) /* Write it out */ > > li t1, DEBUG_LL_UART_DIVISOR > +#if DEBUG_LL_UART_DIVISOR == 0 > + move t1, a0 > +#endif > sb t1, UART_DLL(t0) /* write low order byte */ > srl t1, t1, 8 > sb t1, UART_DLM(t0) /* write high order byte */ > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
