From mboxrd@z Thu Jan 1 00:00:00 1970 From: michael@ellerman.id.au (Michael Ellerman) Date: Wed, 9 Oct 2013 12:34:37 +1100 Subject: [PATCH RFC 00/77] Re-design MSI/MSI-X interrupts enablement pattern In-Reply-To: <20131008073301.GC10669@dhcp-26-207.brq.redhat.com> References: <20131008043330.GF31666@concordia> <20131008073301.GC10669@dhcp-26-207.brq.redhat.com> Message-ID: <20131009013437.GC23780@concordia> On Tue, Oct 08, 2013@09:33:02AM +0200, Alexander Gordeev wrote: > 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? It's not 19/58, it's 33/58. As to how many we care about on powerpc I can't say, so you have a point there. But I still think the interface is not actually that terrible. cheers