Re: [PATCH] hw/char/pl011: Enable TxFIFO and async transmission

[Gavin Shan]

On 2/21/20 8:46 PM, Philippe Mathieu-Daudé wrote:
> On 2/21/20 10:37 AM, Philippe Mathieu-Daudé wrote:
> > Cc'ing Igor & Drew.
> >
> > On 2/21/20 7:28 AM, address@hidden wrote:
> > > Patchew URL: https://patchew.org/QEMU/address@hidden/
> >  >
> > > === TEST SCRIPT BEGIN ===
> > > #!/bin/bash
> > > make docker-image-centos7 V=1 NETWORK=1
> > > time make docker-test-quick@centos7 SHOW_ENV=1 J=14 NETWORK=1
> > > === TEST SCRIPT END ===
> > [...]
> >    TEST    check-qtest-aarch64: tests/qtest/bios-tables-test
> > > **
> > > ERROR:/tmp/qemu-test/src/tests/qtest/acpi-utils.c:145:acpi_find_rsdp_address_uefi:
> > >  code should not be reached
> > > ERROR - Bail out! 
> > > ERROR:/tmp/qemu-test/src/tests/qtest/acpi-utils.c:145:acpi_find_rsdp_address_uefi:
> > >  code should not be reached
> > > make: *** [check-qtest-aarch64] Error 1
> >
> > The virt machine is not happy, busy-looping?
> >
> > $ QTEST_QEMU_BINARY=aarch64-softmmu/qemu-system-aarch64 \
> >    tests/qtest/bios-tables-test
> > /aarch64/acpi/virt: ^C
>
> So this test runs:
>
> $ qemu-system-aarch64 -M virt -pflash pc-bios/edk2-aarch64-code.fd -pflash 
> pc-bios/edk2-arm-vars.fd -cdrom 
> tests/data/uefi-boot-images/bios-tables-test.aarch64.iso.qcow2 -cpu cortex-a57 
> -serial stdio

.../...

> 12638@1582277983.172625:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172629:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172633:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172636:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172640:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172643:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172647:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172650:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172654:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172658:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172661:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172665:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172668:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172672:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172675:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172679:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172682:pl011_read addr 0x00000018 value 0x00000010
> 12638@1582277983.172686:pl011_read addr 0x00000018 value 0x00000010
> [keep looping]

Thanks, Phil. It seems there is some race, which causes the PL011_FLAG_TXFF
isn't cleared properly. It should be fixed in v2, which was just posted.
At least, I didn't see the error locally with v2 :)

   # QTEST_QEMU_BINARY=aarch64-softmmu/qemu-system-aarch64 
tests/qtest/bios-tables-test
     :
   # End of virt tests
   # End of acpi tests
   # End of aarch64 tests

Thanks,
Gavin