> On Fri, Aug 22, 2014 at 12:02:30AM -0000, subha...@codeaurora.org wrote: >> >> + /* >> >> + * put runtime pm reference for well-known logical units, >> >> + * drivers are expected to _get_* again during probe. >> >> + */ >> >> + if (scsi_is_wlun(sdev->lun)) >> >> + scsi_autopm_put_device(sdev); >> > Special casing the well known LUNs here seems wrong. Shouldn't we do >> this >> > for any devices that don't get a driver attached to them? >> >> Agreed, i will replace "if (scsi_is_wlun(sdev->lun))" check with "if >> (sdev->sdev_gendev.driver)". > > I would really prefer the callers of autopm get/put to be symmetric to > issues with later than probe driver attach or similar. Think of the > case say the CDROM or tape driver only gets loaded after we already > did a bus scan. A quick check of the autopm code and it's underlying > implementation seems to suggest that nesting them is okay. If that's > indeed the case I would suggest to restructure it the following way: > > - make the scsi_autopm_put_device call you add at the end of > scsi_sysfs_add_sdev unconditional to make it balance out > the get earlier in the function (and delete the now incorrect comment > above the scsi_autopm_get_device call). > - let drivers do paired get/put calls in their probe/remove methods. > > If you still need any wlun changes after that please send them as a > separate patch with a detailed description on why you need it.
Thanks, yes I was also thinking on same lines but was not sure if it would work or not. But let me check this more and if it works, will make a different patch for it. > All in all the autopm code and it's underlying implementation is highly > confusing, so additional documentation on it would also be very welcome. I would agree but not sure if I would be able to add it now, hopefully some time in future. > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
