On Thu, Nov 06, 2014 at 11:26:01AM +0900, SeokYeon Hwang wrote: > > > > -----Original Message----- > > From: Paolo Bonzini [mailto:paolo.bonz...@gmail.com] On Behalf Of Paolo > > Bonzini > > Sent: Wednesday, November 05, 2014 11:55 PM > > To: Michael S. Tsirkin > > Cc: Markus Armbruster; SeokYeon Hwang; qemu-devel@nongnu.org > > Subject: Re: [Qemu-devel] [PATCH] pci: fixed mismatch of error-handling > > between pci_qdev_init() and qdev > > > > > > > > On 05/11/2014 14:28, Michael S. Tsirkin wrote: > > > > I think bypassing the question by converting to realize makes the > > > > most sense... > > > > > > I'm fine with doing that but Markus's patches wouldn't yet have solved > > > the problem by themselves since init is still around, right? > > > > > > This probably means fixing this bug can't justify merging the realize > > > patchset after freeze. > > > > Yes, I agree. I meant that the API is not very well defined. I would > > handle everything else on a case-by-case basis, by reviewing each init > > function that is converted to realize. > > > > Since the patch was for an out-of-tree device, it can wait for 2.3 anyway. > > > > Paolo > > I cannot fully understand your conversation. > But, I think this patch is still worth before all 'init()' convert to > 'realize()'. > Moreover, It has no side effect at all. > > Thanks. >
The root cause is API misuse: functions that return int should return a negative code on failure, either 0 or >= 0 on success. In rare cases, we use int as bool, so 0 on failure, 1 on success. Your device returned 1 on failure, this broke things. So don't do this then :) The question would be: are there existing devices that return a positive return code on init. If there are, it's a bug, but the best fix might be your patch - easier that fixing many devices. If there aren't, the patch isn't needed. -- MST
