Messages in this thread | | | From | Matt_Domsch@Dell ... | Subject | devicefs requests | Date | Wed, 25 Sep 2002 14:28:57 -0500 |
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Pat,
1) As new drivers pick up the model, check that all xxx_bus_type objects get EXPORT_SYMBOLd and included in a include/xxxx header somewhere - My BIOS EDD code walks the list of bus types looking for attached devices to compare against (pci, ide, scsi, usb, ...). ide_bus_type is in include/linux/ide.h but isn't EXPORT_SYMBOL; usb_bus_type is in include/linux/usb.h but isn't EXPORT_SYMBOL;
Alternately, keep the list of registered bus types accessible via a list_for_each type macro. I like the exported symbols myself, it lets me do:
struct edd_known_bus_types_s { struct bus_type *bus; const char *edd_type; int (*match)(struct device *edd_dev, struct device *dev); };
static const struct edd_known_bus_types_s edd_known_bus_types[] = { {bus:&scsi_driverfs_bus_type, edd_type: "SCSI", match: edd_match_scsidev}, // {bus:&ide_bus_type, edd_type: "ATA", match: NULL}, // {bus:&usb_bus_type, edd_type: "USB", match: NULL}, {bus:NULL, edd_type: NULL, match: NULL}, };
so I can supply my own match functions which match one type of device (e.g. EDD's idea of a SCSI device) to that of the standard device. I could accomplish the same using well-known names for bus_type I suppose, and doing a list_for_each until I find it. Just a different thing getting exported, a well-known name and a lookup method rather than the symbol itself.
2) bus_for_each_dev() is really restrictive right now due to all the locking mechanisms in place. In my code I'd like to, given a struct device *, walk a list of devices on a given bus and compare each device with the given device, returning a match, or not. As it stands, bus_for_each_dev returns either success (the callback worked for each device on the list), or failure (the callback failed for some device on the list), but I don't see a mechanism to return which device failed without excessive abuse of the void*. For now I've made a private copy of bus_for_each_dev which I've mucked with the return the properly matching device, and wonder if this couldn't be made more generic somehow.
Thoughts?
Thanks, Matt
-- Matt Domsch Sr. Software Engineer, Lead Engineer, Architect Dell Linux Solutions www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com
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