From: David Laight <David.Laight@ACULAB.COM>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
Jason Gunthorpe <jgg@nvidia.com>,
"Bjorn Helgaas" <bhelgaas@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Christoph Hellwig <hch@infradead.org>
Subject: revert bab65e48cb064 PCI/MSI Sanitize MSI-X checks
Date: Thu, 6 Apr 2023 11:05:14 +0000 [thread overview]
Message-ID: <caca6879210940428e0aa2a1496907ab@AcuMS.aculab.com> (raw)
The change in bab65e48cb064 breaks pci_enable_msix_range().
The intent is to optimise the sanity checks, but it is
somewhat overenthusiastic.
The interface allows you to ask for a lot of vectors and
returns the number that were allocated.
However, after the change, you can't request a vector
that is higher than the largest the hardware supports.
Which makes that rather pointless.
So code like:
for (i = 0; i < 16; i++)
msix_tbl[i].entry = i;
nvec = pci_enable_msix_range(dev, msix_tbl, 1, 16);
Now returns -22 if the hardware only supports 8 interrupts.
Previously it returned 8.
I can fix my driver, but I suspect that any code that relies
on a smaller number of vectors being returned is now broken.
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next reply other threads:[~2023-04-06 11:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-06 11:05 David Laight [this message]
2023-04-06 15:07 ` revert bab65e48cb064 PCI/MSI Sanitize MSI-X checks Bjorn Helgaas
2023-04-06 15:36 ` David Laight
2023-04-06 19:46 ` Thomas Gleixner
2023-04-06 19:35 ` Linus Torvalds
2023-04-06 21:06 ` Thomas Gleixner
2023-04-07 12:25 ` David Laight
2023-04-07 19:26 ` Linus Torvalds
2023-04-07 21:31 ` Thomas Gleixner
2023-04-10 19:14 ` [PATCH] PCI/MSI: Remove over-zealous hardware size check in pci_msix_validate_entries() Thomas Gleixner
2023-04-15 21:21 ` [tip: irq/urgent] " tip-bot2 for Thomas Gleixner
2023-04-16 12:18 ` tip-bot2 for Thomas Gleixner
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