From: Konrad Rzeszutek Wilk Date: Wed, 3 Dec 2014 21:40:26 +0000 (-0500) Subject: xen/pciback: Don't deadlock when unbinding. X-Git-Tag: omap-for-v3.19/fixes-rc1~121^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8801a7418dda995a70f30874aef77e6d064828e;p=pandora-kernel.git xen/pciback: Don't deadlock when unbinding. As commit 0a9fd0152929db372ff61b0d6c280fdd34ae8bdb 'xen/pciback: Document the entry points for 'pcistub_put_pci_dev'' explained there are four entry points in this function. Two of them are when the user fiddles in the SysFS to unbind a device which might be in use by a guest or not. Both 'unbind' states will cause a deadlock as the the PCI lock has already been taken, which then pci_device_reset tries to take. We can simplify this by requiring that all callers of pcistub_put_pci_dev MUST hold the device lock. And then we can just call the lockless version of pci_device_reset. To make it even simpler we will modify xen_pcibk_release_pci_dev to quality whether it should take a lock or not - as it ends up calling xen_pcibk_release_pci_dev and needs to hold the lock. Reviewed-by: Boris Ostrovsky Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- Reading git-diff-tree failed