From mboxrd@z Thu Jan 1 00:00:00 1970 From: agordeev@redhat.com (Alexander Gordeev) Date: Tue, 8 Oct 2013 09:33:02 +0200 Subject: [PATCH RFC 00/77] Re-design MSI/MSI-X interrupts enablement pattern In-Reply-To: <20131008043330.GF31666@concordia> References: <20131008043330.GF31666@concordia> Message-ID: <20131008073301.GC10669@dhcp-26-207.brq.redhat.com> On Tue, Oct 08, 2013@03:33:30PM +1100, Michael Ellerman wrote: > On Wed, Oct 02, 2013@12:29:04PM +0200, Alexander Gordeev wrote: > > This technique proved to be confusing and error-prone. Vast share > > of device drivers simply fail to follow the described guidelines. > > To clarify "Vast share of device drivers": > > - 58 drivers call pci_enable_msix() > - 24 try a single allocation and then fallback to MSI/LSI > - 19 use the loop style allocation as above > - 14 try an allocation, and if it fails retry once > - 1 incorrectly continues when pci_enable_msix() returns > 0 > > So 33 drivers (> 50%) successfully make use of the "confusing and > error-prone" return value. Ok, you caught me - 'vast share' is incorrect and is a subject to rewording. But out of 19/58 how many drivers tested fallbacks on the real hardware? IOW, which drivers are affected by the pSeries quota? > And yes, one is buggy, so obviously the interface is too complex. Thanks > drivers/ntb/ntb_hw.c vmxnet3 would be the best example. > cheers -- Regards, Alexander Gordeev agordeev at redhat.com