On Sat, Nov 28, 2015 at 06:40:03PM +0200, Jarkko Sakkinen wrote: > On Thu, Nov 26, 2015 at 01:30:31PM -0700, Jason Gunthorpe wrote: > > On Thu, Nov 26, 2015 at 08:01:34PM +0100, martin.wi...@ts.fujitsu.com wrote: > > > From: Martin Wilck <martin.wi...@ts.fujitsu.com> > > > > > > Since b8b2c7d845d5, platform_drv_probe() is called for all platform > > > devices. If drv->probe is NULL, and dev_pm_domain_attach() fails, > > > platform_drv_probe() will return the error code from > > > dev_pm_domain_attach(). > > > > > > This causes real_probe() to enter the "probe_failed" path and set > > > dev->driver to NULL. Before b8b2c7d845d5, real_probe() would assume > > > success if both dev->bus->probe and drv->probe are missing. > > > > > > This may cause a panic later. For example, inserting the tpm_tis > > > driver with parameter "force=1" (i.e. registering tpm_tis as a platform > > > driver) will panic in tpmm_chip_alloc() because dev->driver is NULL: > > > > > > chip->cdev.owner = chip->pdev->driver->owner; > > > > Is this happening because tpm_tis is not creating the platform device > > properly? ie it just calls platform_device_register_simple and then > > force initializes it via tpm_tis_init, which expects to be called from > > a probe function with an attached driver. > > Agreed. We should have a probe callback. > > > Instead we should setup a proper platform device with the default > > IO range for x86 and let the driver core call tpm_tis_init via > > tis_drv.probe. > > > > Would changing things in this way fix the problem you've observed? > > > > I have some patches to do this that are part of my OF enablement > > series, but I can make something simpler that would deal with this > > fairly quickly if you can test. > > Does the patch set that you sent include the fix or not? I haven't yet > reviewed them properly.
Another question: does you patch series include an alternative fix for the probe bug or should I just pick Martins fix? As I sad previously I was seriously lost with the race but now I understand what you and Martin were saying (and feel utterly stupid + ashamed!). Now I'm just thinking, which fix I should pick. Anyway, I'll try to go through your code ASAP. /Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
