Re: [RFC]disable msi mode in pci_disable_device

[Andrew Morton <akpm@osdl.org>]

Shaohua Li <shaohua.li@intel.com> wrote:
>
> Brice said the pci_save_msi_state breaks his driver in his special usage
> (not in suspend/resume), as pci_save_msi_state will disable msi mode.

That sounds wrong of pci_save_msi_state().  It's supposed to save the
state, not to go fiddling with it.

> In
> his usage, pci_save_state will be called at runtime, and later (after
> the device operates for some time and has an error) pci_restore_state
> will be called.

Is that a sane thing for a driver to be doing?  (Not relevant to this issue
though).

> In another hand, suspend/resume needs disable msi mode, as device should
> stop working completely. This patch try to workaround this issue.
> Drivers are expected call pci_disable_device in suspend time after
> pci_save_state.

Surely the drivers should be calling pci_disable_msix() or something after
saving the state rather than relying upon magical side-effects of
pci_save_msi_state().  Or we do disable_msi_mode() or whatever in
pci_disable_device().