The reservation mode of interrupts in kernel assigns a dummy vector when the interrupt is allocated and assigns a real vector when the request_irq is called. The reservation mode helps to ease vector pressure when devices with a large amount of queues/interrupts are initialized, but only a minimal subset of those queues/interrupts is actually used. So on reservation mode, the msi_data may change after request_irq is called, so ath11k reads msi_data again after request_irq is called, and then the correct msi_data is programmed into QCA6390 hardware components. Without this change, spurious interrupt occurs in case of one MSI vector. When VT-d in BIOS is enabled and ath11k can get 32 MSI vectors, ath11k always get the same msi_data before and after request_irq, that's why this change is only required when one MSI vector is to be supported. Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1 Signed-off-by: Carl Huang <cjhuang@codeaurora.org> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20211026041636.5008-1-bqiang@codeaurora.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.
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