Hi Paolo, On Tue, Sep 11, 2018 at 3:11 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > On 05/09/2018 15:11, Geert Uytterhoeven wrote: > > As of commit 18e8cf159177100e ("serial: sh-sci: increase RX FIFO trigger > > defaults for (H)SCIF") in Linux v4.11-rc1, the serial console on the > > QEMU SH4 target is broken: it delays serial input until enough data has > > been received. > > > > Since aforementioned commit, the Linux SCIF driver programs the Receive > > FIFO Data Count Trigger bits in the FIFO Control Register, to postpone > > generating a receive interrupt until: > > 1. At least the receive trigger count of bytes of data are available > > in the receive FIFO, OR > > 2. No further data has been received for at least 15 etu after the > > last received data. > > > > While QEMU implements the former, it does not implement the latter. > > Hence the receive interrupt is not generated until the former condition > > is met. > > > > Fix this by adding basic timeout handling. As the QEMU SCIF emulation > > ignores any serial speed programming, the timeout value used conforms to > > a default speed of 9600 bps, which is fine for any interactive console. > > > > Reported-by: Rob Landley <rob@xxxxxxxxxxx> > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > > Tested-by: Ulrich Hecht <uli@xxxxxxxx> > > Tested-by: Rob Landley <rob@xxxxxxxxxxx> > > Tested-by: Rich Felker <dalias@xxxxxxxx> > Queued, thanks. Does that mean it should show up in qemu.git anytime soon? Thanks, and have a nice weekend! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds