Of all the gin joints in all the towns in all the world, Bill Paul had to walk into mine at 13:45 on Thursday 15 March 2018 and say:
> Of all the gin joints in all the towns in all the world, Andrey Smirnov had > to > > walk into mine at 12:11 on Thursday 15 March 2018 and say: > > Add support for "TX complete"/TXDC interrupt generate by real HW since > > it is needed to support guests other than Linux. > > > > Based on the patch by Bill Paul as found here: > > https://bugs.launchpad.net/qemu/+bug/1753314 > > > > Cc: qemu-devel@nongnu.org > > Cc: qemu-...@nongnu.org > > Cc: Bill Paul <wp...@windriver.com> > > Cc: Peter Maydell <peter.mayd...@linaro.org> > > Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com> > > --- > > > > Bill: > > > > I only tested this with i.MX7/Linux guest combo and am hoping you can > > take this and previous patch and give it a try on your VxWorks setup. > > I tried it and it seems to work as well as my original patch did. There is > one thing I noticed, which is that when printing a lot of output to the > console, sometimes the output will stall until you press a key to generate > an input interrupt, and then it resumes. This happens with my original > patch too. My suspicion is that this has to do with the lack of emulation > of the FIFO feature of the i.MX6 UART, but I'm not certain. (It's still > much better than not having it work at all, so I didn't really mind this. > :) ) All I know for sure is that the stalls don't happen on real hardware. In retrospect, I think the problem may not be with the UART emulation. I went back and created a uniprocessor VxWorks image instead of an SMP image, and it doesn't seem to have the same stall behavior. I added a vxWorks_up image to the URL below so that you can try that too. It may well be that having more than a 1 byte FIFO would fix the problem with the SMP image too, but I don't want to force you to implement that. If you want to try to fix the issue, great, otherwise I am happy with the patch as it is, so I will provide this: Signed-off-by: Bill Paul <wp...@windriver.com> -Bill > > FYI, I uploaded a sample VxWorks image that you can use for testing. You > can find it here: > > http://people.freebsd.org/~wpaul/qemu/sabrelite > > The file vxWorks is the kernel, which is really all you need. This is an > SMP image so you need to run QEMU with the -smp 4 option. The uVxWorks > image and .dtb file are used on a real board with U-Boot and the bootm > command. The qemu_imx.sh script contains the options I use for testing. I > usually do: > > % qemu_imx.sh vxWorks > > You can download all the files at once by grabbing: > > http://people.freebsd.org/~wpaul/qemu/sabrelite/vxworks_test.zip > > At the -> prompt, you can type the following things (among others): > > -> i -- show running task info > -> vxbIoctlShow -- show VxBus device tree > -> vxbDevShow -- show VxBus device tree in a different format > -> vxbDrvShow -- show VxBus drivers > -> vxbIntShow -- show information about interrupt bindings > -> vmContextShow -- show MMU mappings > -> memShow -- show heap usage > -> ifconfig -- show network interfaces > -> routec "show" -- show network routing table > -> netstat "-a" -- show network socket info > > The image also includes network support. You can use ifconfig to set the > enet0 interface's addresss like this: > > -> ifconfig "enet0 10.0.2.15 netmask 255.255.255.0 up" > > You should then be able to telnet to the VxWorks image from the host > machine by doing: > > % telnet localhost 10023 > > To exit the telnet session, type logout: > > -> logout > > NOTE: this only works if you've patched the imx_fec module to fix the > interrupt vector bug that I also reported. > > If you run vxbIoctlShow, which generates a lot of output, you should be > able to see the stall condition I'm talking about. If you don't, then > maybe it has something to do with me running QEMU on FreeBSD. > > > Peter: > > > > Bill is the author of original code, so I am not sure how to handle > > Signed-off-by from him. I'd like to add it to this patch, but since > > his original submission to launchpad didn't have one it is currently > > omitted. > > My original goal was to report the bug and provide as much info as I could > on how to maybe fix it, and let somebody else make a proper fix/patch. > > -Bill > > > include/hw/char/imx_serial.h | 3 +++ > > hw/char/imx_serial.c | 20 +++++++++++++++++--- > > 2 files changed, 20 insertions(+), 3 deletions(-) > > > > diff --git a/include/hw/char/imx_serial.h b/include/hw/char/imx_serial.h > > index baeec3183f..5b99cee7cf 100644 > > --- a/include/hw/char/imx_serial.h > > +++ b/include/hw/char/imx_serial.h > > @@ -67,6 +67,8 @@ > > > > #define UCR2_RXEN (1<<1) /* Receiver enable */ > > #define UCR2_SRST (1<<0) /* Reset complete */ > > > > +#define UCR4_TCEN BIT(3) /* TX complete interrupt enable */ > > + > > > > #define UTS1_TXEMPTY (1<<6) > > #define UTS1_RXEMPTY (1<<5) > > #define UTS1_TXFULL (1<<4) > > > > @@ -95,6 +97,7 @@ typedef struct IMXSerialState { > > > > uint32_t ubmr; > > uint32_t ubrc; > > uint32_t ucr3; > > > > + uint32_t ucr4; > > > > qemu_irq irq; > > CharBackend chr; > > > > diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c > > index d1e8586280..1e5540472b 100644 > > --- a/hw/char/imx_serial.c > > +++ b/hw/char/imx_serial.c > > @@ -37,8 +37,8 @@ > > > > static const VMStateDescription vmstate_imx_serial = { > > > > .name = TYPE_IMX_SERIAL, > > > > - .version_id = 1, > > - .minimum_version_id = 1, > > + .version_id = 2, > > + .minimum_version_id = 2, > > > > .fields = (VMStateField[]) { > > > > VMSTATE_INT32(readbuff, IMXSerialState), > > VMSTATE_UINT32(usr1, IMXSerialState), > > > > @@ -50,6 +50,7 @@ static const VMStateDescription vmstate_imx_serial = { > > > > VMSTATE_UINT32(ubmr, IMXSerialState), > > VMSTATE_UINT32(ubrc, IMXSerialState), > > VMSTATE_UINT32(ucr3, IMXSerialState), > > > > + VMSTATE_UINT32(ucr4, IMXSerialState), > > > > VMSTATE_END_OF_LIST() > > > > }, > > > > }; > > > > @@ -71,6 +72,11 @@ static void imx_update(IMXSerialState *s) > > > > * unfortunately. > > */ > > > > mask = (s->ucr1 & UCR1_TXMPTYEN) ? USR2_TXFE : 0; > > > > + /* > > + * TCEN and TXDC are both bit 3 > > + */ > > + mask |= s->ucr4 & UCR4_TCEN; > > + > > > > usr2 = s->usr2 & mask; > > > > qemu_set_irq(s->irq, usr1 || usr2); > > > > @@ -163,6 +169,8 @@ static uint64_t imx_serial_read(void *opaque, hwaddr > > offset, return s->ucr3; > > > > case 0x23: /* UCR4 */ > > > > + return s->ucr4; > > + > > > > case 0x29: /* BRM Incremental */ > > > > return 0x0; /* TODO */ > > > > @@ -191,8 +199,10 @@ static void imx_serial_write(void *opaque, hwaddr > > offset, * qemu_chr_fe_write and background I/O callbacks */ > > > > qemu_chr_fe_write_all(&s->chr, &ch, 1); > > s->usr1 &= ~USR1_TRDY; > > > > + s->usr2 &= ~USR2_TXDC; > > > > imx_update(s); > > s->usr1 |= USR1_TRDY; > > > > + s->usr2 |= USR2_TXDC; > > > > imx_update(s); > > > > } > > break; > > > > @@ -265,8 +275,12 @@ static void imx_serial_write(void *opaque, hwaddr > > offset, s->ucr3 = value & 0xffff; > > > > break; > > > > - case 0x2d: /* UTS1 */ > > > > case 0x23: /* UCR4 */ > > > > + s->ucr4 = value & 0xffff; > > + imx_update(s); > > + break; > > + > > + case 0x2d: /* UTS1 */ > > > > qemu_log_mask(LOG_UNIMP, "[%s]%s: Unimplemented reg 0x%" > > > > HWADDR_PRIx "\n", TYPE_IMX_SERIAL, __func__, > > > > offset); /* TODO */ -- ============================================================================= -Bill Paul (510) 749-2329 | Senior Member of Technical Staff, wp...@windriver.com | Master of Unix-Fu - Wind River Systems ============================================================================= "I put a dollar in a change machine. Nothing changed." - George Carlin =============================================================================
