Is multiple uio's for single device supported?

From: divakar
Date: Wed Sep 07 2016 - 20:11:26 EST


Hi

My fpga device has multiple msi interrupts and I am trying to create an
uio device for each msi interrupt. In the probe function of the pci
device, I enable MSI for the pci device and allocate mem for uio info
structures ( one for each msi ). First uio-info->irq is equal to the irq
number in pdev->irq and It successfully creates /dev/uio-0 . For the
second msi i assign uio_info->irq = pdev->irq + 1 and different
uio_info->name, but uio_register_device fails. When traced it fails at
the devm_request_irq function. I am running on 3.19 kernel and after
checking the latest 4.7 I noticed devm_request has changed to
request_irq. I get the same error even with request_irq.

- Does the uio framework support multiple uio's for the same pci device?
- if yes, is there something extra i need to do ?

Please let me know if I can provide any more information. Below is the
log from my driver.

103 fpga_uio_probe FPGA_PCI_UIO: probe
105 fpga_uio_probe FPGA_PCI_UIO: bar_base=183fffc00000
107 fpga_uio_probe FPGA_PCI_UIO: bar_len=1048576
125 fpga_uio_probe FPGA_PCI_UIO: pci_enable_device
132 fpga_uio_probe FPGA_PCI_UIO: pci_request_region
147 fpga_uio_probe FPGA_PCI_UIO: pci_iomap
153 fpga_uio_probe FPGA_PCI_UIO: base_add=ffffc90012a00000
169 fpga_uio_probe FPGA_PCI_UIO: nmsi_requested =8
211 fpga_uio_probe FPGA_PCI_UIO: irq_starting_indx =101
219 fpga_uio_probe FPGA_PCI_UIO: alloc mem for fpudev
226 fpga_uio_probe FPGA_PCI_UIO: alloc mem for uio_info
233 fpga_uio_probe FPGA_PCI_UIO: alloc mem for uio_priv_info
298 fpga_uio_probe FPGA_PCI_UIO: reg uio dev
__uio_register_device 805
__uio_register_device 813
__uio_register_device 819
__uio_register_device 821 get_minor ret=0
__uio_register_device 825
__uio_register_device 835
__uio_register_device 840
__uio_register_device 846 devm_request ret=0
__uio_register_device 851
311 fpga_uio_probe FPGA_PCI_UIO: Enable all INT

298 fpga_uio_probe FPGA_PCI_UIO: reg uio dev
__uio_register_device 805
__uio_register_device 813
__uio_register_device 819
__uio_register_device 821 get_minor ret=0
__uio_register_device 825
__uio_register_device 835
__uio_register_device 840
__uio_register_device 846 devm_request ret=-22
304 fpga_uio_probe FPGA_PCI_UIO: Failed to register uio devicefor
msi=102, irq=1 ret=-22

Thanks