9088614323
[ Upstream commit 63cd736f449445edcd7f0bcc7d84453e9beec0aa ]
Some ATI SB600 USB adapters advertise MSI, but if INTx is disabled by
setting PCI_COMMAND_INTX_DISABLE, MSI doesn't work either. The PCI/PCIe
specs do not require software to set PCI_COMMAND_INTX_DISABLE when enabling
MSI, but Linux has done that for many years.
Mick reported that 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI
devices") broke these devices. Prior to 306c54d0edb6, they used INTx.
Starting with 306c54d0edb6, they use MSI, and and the fact that Linux sets
PCI_COMMAND_INTX_DISABLE means both INTx and MSI are disabled on these
devices.
Avoid this SB600 defect by disabling MSI so we use INTx as before.
Fixes: 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices")
Link: https://lore.kernel.org/r/20220321183446.1108325-1-helgaas@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215690
Link: https://lore.kernel.org/all/PxIByDyBRcsbpcmVhGSNDFAoUcMmb78ctXCkw6fbpx25TGlCHvA6SJjjFkNr1FfQZMntYPTNyvEnblxzAZ8a6jP9ddLpKeCN6Chi_2FuexU=@protonmail.com/
Link: https://lore.kernel.org/r/20220314101448.90074-1-andriy.shevchenko@linux.intel.com
BugLink: https://lore.kernel.org/all/20200702143045.23429-1-andriy.shevchenko@linux.intel.com/
Reported-by: Mick Lorain <micklorain@protonmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.