| Message ID | 1449132704-9952-1-git-send-email-martin.wilck@ts.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Martin, On Thu, Dec 03, 2015 at 09:51:44AM +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 were missing. As a result, > a device and driver could be "bound" together just by matching their names; > this doesn't work any more after b8b2c7d845d5. > > This change broke the assumptions of certain drivers; for example, the TPM > code has long assumed that platform driver and device with matching name > could be bound in this way. That assumption may cause such drivers to > fail with Oops during initialization after applying this change. Failure > in suspend/resume tests under qemu has also been reported. > > This patch restores the previous (4.3.0 and earlier) behavior of > platform_drv_probe() in the case when 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: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Thanks Uwe
On Thu, Dec 03, 2015 at 09:51:44AM +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 were missing. As a result, > a device and driver could be "bound" together just by matching their names; > this doesn't work any more after b8b2c7d845d5. > > This change broke the assumptions of certain drivers; for example, the TPM > code has long assumed that platform driver and device with matching name > could be bound in this way. That assumption may cause such drivers to > fail with Oops during initialization after applying this change. Failure > in suspend/resume tests under qemu has also been reported. > > This patch restores the previous (4.3.0 and earlier) behavior of > platform_drv_probe() in the case when 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> > --- > v2: fixed style issues, rephrased commit message. > v3: rephrased commit message and subject again. > > drivers/base/platform.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 1dd6d3b..176b59f 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -513,10 +513,15 @@ static int platform_drv_probe(struct device *_dev) > return ret; > > ret = dev_pm_domain_attach(_dev, true); > - if (ret != -EPROBE_DEFER && drv->probe) { > - ret = drv->probe(dev); > - if (ret) > - dev_pm_domain_detach(_dev, true); > + if (ret != -EPROBE_DEFER) { > + if (drv->probe) { > + ret = drv->probe(dev); > + if (ret) > + dev_pm_domain_detach(_dev, true); > + } else { > + /* don't fail if just dev_pm_domain_attach failed */ > + ret = 0; > + } > } > > if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) { > -- > 1.8.3.1 Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> /Jarkko ------------------------------------------------------------------------------ Go from Idea to Many App Stores Faster with Intel(R) XDK Give your users amazing mobile app experiences with Intel(R) XDK. Use one codebase in this all-in-one HTML5 development environment. Design, debug & build mobile apps & 2D/3D high-impact games for multiple OSs. http://pubads.g.doubleclick.net/gampad/clk?id=254741911&iu=/4140
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 1dd6d3b..176b59f 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -513,10 +513,15 @@ static int platform_drv_probe(struct device *_dev) return ret; ret = dev_pm_domain_attach(_dev, true); - if (ret != -EPROBE_DEFER && drv->probe) { - ret = drv->probe(dev); - if (ret) - dev_pm_domain_detach(_dev, true); + if (ret != -EPROBE_DEFER) { + if (drv->probe) { + ret = drv->probe(dev); + if (ret) + dev_pm_domain_detach(_dev, true); + } else { + /* don't fail if just dev_pm_domain_attach failed */ + ret = 0; + } } if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {