On Wed, Mar 04, 2015 at 09:22:37AM +0100, Wolfram Sang wrote: > > > > > I am writing an I2C touchscreen driver for an i.MX6 based board. I > > > > compiled it as a module and when I unload it, I get the following warning: > > > > > > > > # modprobe sx8654 > > > > [ 46.261494] input: SX8654 I2C Touchscreen as > > > > /devices/soc0/soc/2100000.aips-bus/21a0000.i2c/i2c-0/0-0048/input/input1 > > > > # rmmod sx8654 > > > > [ 76.435223] ------------[ cut here ]------------ > > > > [ 76.439909] WARNING: CPU: 0 PID: 134 at fs/proc/generic.c:552 > > > > remove_proc_entry+0x148/0x164() > > > > [ 76.448582] remove_proc_entry: removing non-empty directory > > > > 'irq/208', leaking at least 'sx8654' > > > > > > ... > > > > > > > When I revert commit e4df3a0 (i2c: core: Dispose OF IRQ mapping at > > > > client removal time) I don't get the warning. > > > > > > > > Is this a bug in the i2c-core or am I doing something wrong in my driver? > > > > > > Yes, this commit breaks all drivers using devm* for IRQ management on > > > OF-based systemsi because devm* cleanup happens in device code, after > > > bus's remove() method returns. I'd recommend reverting and finding a > > > better way (making cleanup a custom devm action as well?). > > > > Ouch, my bad. > > > > Wolfram, any opinion ? The original patch fixes a real bug, so we shouldn't > > just revert it. > > Looking at it some more: What bug does it fix? Anything you experienced? > > I wonder if we really need e4df3a0 because I can't see where > platform_get_irq, the major user of of_irq_get, disposes the mapping. > irq_create_of_mapping() will return an already assigned mapping if > called twice. I don't know yet, though, if mappings are static or if a > mapping can be routed to another irq controller over some time because > theoretically they can be dynamically added/removed. > > Adding Rob to CC as he wrote of_irq_get and put it into > platform_get_irq. Rob, we use of_irq_get() in the I2C core and the > question is now if we need to dispose the mapping and if so what would > be a good place for it so managed devices will not have their mappings > removed before the managed irq is removed. Ping. Just so you know: Without further information, I will revert the patch in question around rc4/rc5. I'd still like to know if the non-disposing of the mapping in platform_get_irq() is intentional. Thanks, Wolfram
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