Messages in this thread | | | Date | Sun, 29 Nov 2015 10:54:11 +0100 | From | Uwe Kleine-König <> | Subject | Re: [tpmdd-devel] [PATCH] base/platform: fix panic when probe function is NULL |
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Hello Jarkko,
On Sat, Nov 28, 2015 at 06:34:47PM +0200, Jarkko Sakkinen wrote: > On Thu, Nov 26, 2015 at 08:01:34PM +0100, martin.wilck@ts.fujitsu.com wrote: > > From: Martin Wilck <Martin.Wilck@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; > > > > This patch fixes this by returning success in platform_drv_probe() if > > "just" dev_pm_domain_attach() had failed. This restores the semantics > > of platform_device_register_XXX() if the associated platform driver has > > no "probe" function. > > > > Fixes: b8b2c7d845d5 ("base/platform: assert that dev_pm_domain > > callbacks are called unconditionally") > > > > Signed-off-by: Martin Wilck <Martin.Wilck@ts.fujitsu.com> > > Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
While the patch is fine, the commit log is not. It blames b8b2c7d845d5 to be responsible for a panic, but in fact it only breaks the wrong assumption of the tpm_tis driver.
So I'm not sure how to interpret your Ack, IMHO it should not make gregkh pick up the patch as is.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
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