Hi Rob, CC Adrian, linux-serial, linux-renesas-soc On Fri, Apr 21, 2017 at 8:21 AM, Rob Landley <rob@xxxxxxxxxxx> wrote: > In 4.11-rc7 the qemu serial console hangs after the first character you > type. To reproduce, configure linux with this mini.config: > > CONFIG_CPU_SUBTYPE_SH7751R=y > CONFIG_MMU=y > CONFIG_MEMORY_START=0x0c000000 > CONFIG_VSYSCALL=y > CONFIG_SH_FPU=y > CONFIG_SH_RTS7751R2D=y > CONFIG_RTS7751R2D_PLUS=y > CONFIG_SERIAL_SH_SCI=y > CONFIG_SERIAL_SH_SCI_CONSOLE=y > CONFIG_EARLY_PRINTK=y > CONFIG_BLK_DEV_INITRD=y" > CONFIG_RD_GZIP=y > CONFIG_BINFMT_ELF=y > CONFIG_BINFMT_SCRIPT=y > CONFIG_MISC_FILESYSTEMS=y > CONFIG_DEVTMPFS=y > > Using "make ARCH=sh allnoconfig KCONFIG_ALLCONFIG=mini.conf", then build > the result, then boot under qemu using the following command line: > > qemu-system-sh4 -M r2d -monitor null -serial null -serial stdio > -nographic -no-reboot -append "panic=1 HOST=sh4 console=ttySC1 noiotrap" > -kernel zImage -initrd sh4-linux-musl-root.cpio.gz > > You'll need a simple cpio.gz initramfs (I built one using > https://github.com/landley/mkroot and the musl-cross-make cross > compiler, the cpio.gz is ~450k or I'd attach it here). > > I bisected it to commit 18e8cf159177 back in February. If you do this > with the revision _before_ that commit, typing "ls -l" and hitting enter > works fine. Afterwards you get an "l" and then it hangs. (If type enough > it'll eventually deal a burst of characters all at once, and then hang > again.) SH7751R has both SCI and SCIF ports. ttySC1 is the second (SCIF) port. arch/sh/kernel/cpu/sh4/setup-sh7750.c registers a port with type PORT_SCIF, so that should become SCIx_SH4_SCIF_REGTYPE. Hence I don't think the issue is caused by changing fifosize to 64 for SCIx_SH7705_SCIF_REGTYPE. My first guess is that qemu has a bug emulating the triggering. According to the SH7751R datasheet, SCFCR does have the RTRG1 and RTRG0 bits. I assume the problem goes away if you comment out the call to scif_set_rtrg()? Does anyone have access to real hardware to try? Adrian: does it work on your LANDISK, which also has SH7751R? Thanks! 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
