Andreas Färber <afaer...@suse.de> writes:
> Am 05.02.2014 09:39, schrieb Markus Armbruster:
>> This reverts commit 7426aa72c36c908a7d0eae3e38568bb0a70de479.
>>
>> The commit goes into a sensible direction, but it violates qdev design
>> assumptions. Symptom: "info qtree" crashes for all boards including
>> the device (akita, borzoi, spitz, terrier, tosa, axis-dev88).
>>
>> Peter Crosthwaite is working on a fix, but it's not trivial. Revert
>> the flawed patch for now.
>>
>> Signed-off-by: Markus Armbruster <arm...@redhat.com>
>> Acked-by: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
>> ---
>> hw/block/nand.c | 7 +++----
>> 1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/block/nand.c b/hw/block/nand.c
>> index a871ce0..a0232d1 100644
>> --- a/hw/block/nand.c
>> +++ b/hw/block/nand.c
>> @@ -21,7 +21,7 @@
>> # include "hw/hw.h"
>> # include "hw/block/flash.h"
>> # include "sysemu/blockdev.h"
>> -#include "hw/qdev.h"
>> +# include "hw/sysbus.h"
>> #include "qemu/error-report.h"
>>
>> # define NAND_CMD_READ0 0x00
>> @@ -54,8 +54,7 @@
>>
>> typedef struct NANDFlashState NANDFlashState;
>> struct NANDFlashState {
>> - DeviceState parent_obj;
>> -
>> + SysBusDevice busdev;
>
> Negative on calling it busdev again, that surely has nothing to do with
> a crash since it's not being used anywhere in this patch.
I do not believe in messing with clean reverts such as this one. Any
follow-up cleanup should be a separate patch. The easiest way to tell
me what cleanup you want could be a patch :)
> I still have not seen a single backtrace of what is going wrong, only
> Paolo saying something about adding to main_system_bus in "the patch".
> Clearly that is not in this patch! Where is that happening and why is
> that so complicated for Peter C. to fix?
My commit message should suffice to reproduce: start a qemu for any of
the listed boards, run "info qtree". But I'm happy to spell it out:
$ QEMU_AUDIO_DRV=none ~/work/qemu/bld/arm-softmmu/qemu-system-arm -M akita
-nodefaults -display none -monitor stdio -M akita -sd /dev/null -S
QEMU 1.7.50 monitor - type 'help' for more information
(qemu) info qtree
bus: main-system-bus
type System
dev: scoop, id ""
gpio-in 16
gpio-out 16
irq 0
mmio 0000000010800000/0000000000001000
dev: spitz-keyboard, id ""
gpio-in 11
gpio-out 7
irq 0
dev: nand, id ""
manufacturer_id = 236
chip_id = 241
drive = <null>
/work/armbru/qemu/hw/core/sysbus.c:209:sysbus_dev_print: Object
0x7f750ab9d910 is not an instance of type sys-bus-device
Aborted (core dumped)
Backtrace:
#0 0x00007fffee698c55 in raise () from /lib64/libc.so.6
#1 0x00007fffee69a408 in abort () from /lib64/libc.so.6
#2 0x00005555557bef59 in object_dynamic_cast_assert (obj=0x55555634d910,
typename=typename@entry=0x555555943e4d "sys-bus-device",
file=file@entry=
0x55555594a6f0 "/work/armbru/qemu/hw/core/sysbus.c",
line=line@entry=209,
func=func@entry=0x55555594a940 <__func__.23193> "sysbus_dev_print")
at /work/armbru/qemu/qom/object.c:484
#3 0x00005555556b3c16 in sysbus_dev_print (mon=0x55555625fe00,
dev=<optimized out>, indent=4) at /work/armbru/qemu/hw/core/sysbus.c:209
#4 0x00005555557a2e24 in bus_print_dev (indent=4, dev=0x55555634d910, mon=
0x55555625fe00, bus=<optimized out>)
at /work/armbru/qemu/qdev-monitor.c:599
#5 qdev_print (indent=4, dev=0x55555634d910, mon=0x55555625fe00)
at /work/armbru/qemu/qdev-monitor.c:621
#6 qbus_print (mon=0x55555625fe00, bus=<optimized out>, indent=2)
at /work/armbru/qemu/qdev-monitor.c:636
#7 0x00005555558a8e39 in handle_user_command
(mon=mon@entry=0x55555625fe00,
cmdline=<optimized out>) at /work/armbru/qemu/monitor.c:4144
#8 0x00005555558a91cb in monitor_command_cb (opaque=0x55555625fe00,
cmdline=<optimized out>, readline_opaque=<optimized out>)
at /work/armbru/qemu/monitor.c:4761
#9 0x00005555559276b4 in readline_handle_byte (rs=0x555556273c90,
ch=<optimized out>) at /work/armbru/qemu/util/readline.c:371
---Type <return> to continue, or q <return> to quit---
#10 0x00005555558a8f04 in monitor_read (opaque=<optimized out>,
buf=<optimized out>, size=<optimized out>)
at /work/armbru/qemu/monitor.c:4744
#11 0x00005555557a6eba in qemu_chr_be_write (len=<optimized out>, buf=
0x7fffffffcbd0 "\r", s=0x55555625e400) at
/work/armbru/qemu/qemu-char.c:165
#12 fd_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=
0x55555625e400) at /work/armbru/qemu/qemu-char.c:848
#13 0x00007ffff76f7a55 in g_main_context_dispatch ()
from /lib64/libglib-2.0.so.0
#14 0x0000555555775001 in glib_pollfds_poll ()
at /work/armbru/qemu/main-loop.c:189
#15 os_host_main_loop_wait (timeout=<optimized out>)
at /work/armbru/qemu/main-loop.c:234
#16 main_loop_wait (nonblocking=<optimized out>)
at /work/armbru/qemu/main-loop.c:483
#17 0x0000555555601ed1 in main_loop () at /work/armbru/qemu/vl.c:2018
#18 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>)
at /work/armbru/qemu/vl.c:4410
As to why it's complicated for Peter to fix, here's what Peter wrote:
"That series got very big on me with complications. I think near term
we just proceed with the revert. Sorry for the delay." I have no
reason to second-guess him.
Promptly reverting patches that cause regressions when a fix isn't ready
is standard operating procedure. We can delay a revert a reasonable
amount of time to deliberate what to do, and perhaps find a fix. We did
that, and then some: four weeks. We should revert, and try again.
Neither harm nor shame in that.
A cleanup of nand is quite welcome, but there's absolutely no rush.
[...]
