[Qemu-devel] [Bug 588748] [NEW] QEMU fails to boot DR DOS Plus since 0.6.1

[Qemu-devel] [Bug 588748] [NEW] QEMU fails to boot DR DOS Plus since 0.6.1

[Roy Tam]

Public bug reported:

The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting
Digital Research DOS Plus.

** Affects: qemu
     Importance: Undecided
         Status: New

-- 
QEMU fails to boot DR DOS Plus since 0.6.1
https://bugs.launchpad.net/bugs/588748
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Status in QEMU: New

Bug description:
The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting Digital Research DOS Plus.

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Roy Tam]

** Patch added: "Following patch partially reverts that commit and makes DOSPlus booting in QEMU again."
   http://launchpadlibrarian.net/49557998/serial-ier-fix.patch

-- 
QEMU fails to boot DR DOS Plus since 0.6.1
https://bugs.launchpad.net/bugs/588748
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.

Status in QEMU: New

Bug description:
The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting Digital Research DOS Plus.

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Anthony Liguori]

This patch doesn't seem correct as the spec is pretty clear that THRE
interrupt enable is set to high, then an interrupt is rased if
LSR.THRE=1.  Does the following also make DOSPlus boot again:


diff --git a/hw/serial.c b/hw/serial.c
index 9102edb..b0ac52f 100644
--- a/hw/serial.c
+++ b/hw/serial.c
@@ -401,7 +401,8 @@ static void serial_ioport_write(void *opaque, uint32_t addr,
                      s->poll_msl = 0;
                 }
             }
-            if (s->lsr & UART_LSR_THRE) {
+            if (s->ier & UART_IER_THRI &&
+                s->lsr & UART_LSR_THRE) {
                 s->thr_ipending = 1;
                 serial_update_irq(s);
             }


** Changed in: qemu
       Status: New => In Progress

-- 
QEMU fails to boot DR DOS Plus since 0.6.1
https://bugs.launchpad.net/bugs/588748
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.

Status in QEMU: In Progress

Bug description:
The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting Digital Research DOS Plus.

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Roy Tam]

> This patch doesn't seem correct as the spec is pretty clear that THRE
interrupt enable is set to high, then an interrupt is rased if
LSR.THRE=1. Does the following also make DOSPlus boot again:

No it doesn't. Same as unpatched.

-- 
QEMU fails to boot DR DOS Plus since 0.6.1
https://bugs.launchpad.net/bugs/588748
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.

Status in QEMU: In Progress

Bug description:
The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting Digital Research DOS Plus.

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Anthony Liguori]

Can you add some debugging to see what IER is being set to?

Do you have any insight into why DR DOS Plus is failing?

-- 
QEMU fails to boot DR DOS Plus since 0.6.1
https://bugs.launchpad.net/bugs/588748
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.

Status in QEMU: In Progress

Bug description:
The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting Digital Research DOS Plus.

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Roy Tam]

> Can you add some debugging to see what IER is being set to?

With DEBUG_SERIAL defined, serial logs:
serial: event 2
serial: write addr=0x01 val=0x02
serial: read addr=0x01 val=0x02
serial: read addr=0x02 val=0x02
serial: write addr=0x01 val=0x00
serial: write addr=0x03 val=0x80
serial: write addr=0x00 val=0x0c
serial: write addr=0x01 val=0x00
serial: write addr=0x03 val=0x03
serial: write addr=0x04 val=0x0b
serial: read addr=0x05 val=0x60
serial: read addr=0x06 val=0xb0
serial: read addr=0x00 val=0x00
serial: write addr=0x01 val=0x0f
serial: read addr=0x02 val=0x02
serial: read addr=0x02 val=0x01
(stalls here)

-- 
QEMU fails to boot DR DOS Plus since 0.6.1
https://bugs.launchpad.net/bugs/588748
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.

Status in QEMU: In Progress

Bug description:
The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents booting Digital Research DOS Plus.

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Paolo Bonzini]

I think the interrupt should be raised only on the rising edge of THRE.

** Changed in: qemu
     Assignee: (unassigned) => Paolo Bonzini (bonzini)

-- 
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https://bugs.launchpad.net/bugs/588748

Title:
  QEMU fails to boot DR DOS Plus since 0.6.1

Status in QEMU:
  In Progress

Bug description:
  The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents
  booting Digital Research DOS Plus.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/588748/+subscriptions

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[T. Huth]

Has this bug been fixed by this commit here:
http://git.qemu.org/?p=qemu.git;a=commitdiff;h=1645b8eee558ffe2389
?
If so, I think we could now close this bug ticket...

-- 
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devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/588748

Title:
  QEMU fails to boot DR DOS Plus since 0.6.1

Status in QEMU:
  In Progress

Bug description:
  The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents
  booting Digital Research DOS Plus.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/588748/+subscriptions

[Qemu-devel] [Bug 588748] Re: QEMU fails to boot DR DOS Plus since 0.6.1

[Paolo Bonzini]

** Changed in: qemu
       Status: In Progress => Fix Released

-- 
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https://bugs.launchpad.net/bugs/588748

Title:
  QEMU fails to boot DR DOS Plus since 0.6.1

Status in QEMU:
  Fix Released

Bug description:
  The commit in r1049 (serial interrupt fix (Hampa Hug)) prevents
  booting Digital Research DOS Plus.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/588748/+subscriptions