Messages in this thread | | | Date | Mon, 2 Apr 2012 11:48:54 +0100 | From | Ian Abbott <> | Subject | Re: [PATCH v2] staging: comedi: resolve section mismatch in s626 |
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On 2012-03-19 23:26, Greg KH wrote: > On Mon, Mar 19, 2012 at 03:46:49PM -0700, Gerard Snitselaar wrote: >> On Mon, Mar 19, 2012 at 09:43:25AM -0700, Gerard Snitselaar wrote: >>> On Mon, Mar 19, 2012 at 09:31:03AM -0700, Greg KH wrote: >>>> >>>> Ick, why is this loop even needed? We are only here if the pci device >>>> is present in the system so this shouldn't be needed at all, right? >>>> >>>> Or is this a bit more complex than I am making it out to be? >>>> >>>> greg k-h >>> >>> Most likely not. I will take a look at some of the other drivers in >>> comedi and see how the attach code looks there. I believe the code >>> section in hpdi_attach() was written by the same person. Unfortunately >>> I don't have a device to actually play around and see what changes are >>> doing. >>> >> >> I looked at this a bit more. It looks like they lose visibility to the >> pci_dev structure. >> >> *_probe() >> comedi_pci_auto_config() pci_dev >> comedi_auto_config() pci_dev->dev >> comedi_device_attach() ?? >> driv->attach() ??<= iterate through pci devices. >> >> Most of the examples I have looked at so far use for_each_pci_dev() to >> find the device, and s626 shortcuts it a bit by directly making calls >> to pci_get_subsys() with specific ids. They all verify they have the >> right device by checking the bus and slot that are grabbed from the >> pci_dev in comedi_pci_auto_config() and passed down. > > Ugh, surely there's a way to keep the pci dev through the > comedi_device_attach() call, right?
comedi_device_attach() is also called for the COMEDI_DEVCONFIG ioctl for "manually" configuring a comedi device, and that has no idea about struct pci_dev, etc.
I recently posted a series of patches that allows lower-level comedi drivers to supply separate hooks for auto-configuring PCI devices or USB devices without abusing the old "manual configuration" code paths, see <http://driverdev.linuxdriverproject.org/pipermail/devel/2012-March/025331.html>.
The old loop that searches the PCI bus is still needed for the "manual configuration" code path.
-- -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@mev.co.uk> )=- -=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
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