| Message ID | 1410857494-15936-4-git-send-email-k.kozlowski@samsung.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Tue, Sep 16, 2014 at 10:51:33AM +0200, Krzysztof Kozlowski wrote: > @@ -191,8 +210,11 @@ static int amba_probe(struct device *dev) > pm_runtime_enable(dev); > > ret = pcdrv->probe(pcdev, id); > - if (ret == 0) > + if (ret == 0) { > + if (pm_runtime_is_irq_safe(dev)) > + pcdev->irq_safe = 1; Patch looks good, though I'd prefer this to always explicitly initialise pcdev->irq_safe each time a probe succeeds.
On wto, 2014-09-16 at 10:20 +0100, Russell King - ARM Linux wrote: > On Tue, Sep 16, 2014 at 10:51:33AM +0200, Krzysztof Kozlowski wrote: > > @@ -191,8 +210,11 @@ static int amba_probe(struct device *dev) > > pm_runtime_enable(dev); > > > > ret = pcdrv->probe(pcdev, id); > > - if (ret == 0) > > + if (ret == 0) { > > + if (pm_runtime_is_irq_safe(dev)) > > + pcdev->irq_safe = 1; > > Patch looks good, though I'd prefer this to always explicitly initialise > pcdev->irq_safe each time a probe succeeds. No problem, I'll add this and resend. Thank you for feedback, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 3cf61a127ee5..4aee6e61bed2 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -94,8 +94,18 @@ static int amba_pm_runtime_suspend(struct device *dev) struct amba_device *pcdev = to_amba_device(dev); int ret = pm_generic_runtime_suspend(dev); - if (ret == 0 && dev->driver) - clk_disable_unprepare(pcdev->pclk); + if (ret == 0 && dev->driver) { + /* + * Drivers should not change pm_runtime_irq_safe() + * after probe. + */ + WARN_ON(pcdev->irq_safe != pm_runtime_is_irq_safe(dev)); + + if (pcdev->irq_safe) + clk_disable(pcdev->pclk); + else + clk_disable_unprepare(pcdev->pclk); + } return ret; } @@ -106,7 +116,16 @@ static int amba_pm_runtime_resume(struct device *dev) int ret; if (dev->driver) { - ret = clk_prepare_enable(pcdev->pclk); + /* + * Drivers should not change pm_runtime_irq_safe() + * after probe. + */ + WARN_ON(pcdev->irq_safe != pm_runtime_is_irq_safe(dev)); + + if (pcdev->irq_safe) + ret = clk_enable(pcdev->pclk); + else + ret = clk_prepare_enable(pcdev->pclk); /* Failure is probably fatal to the system, but... */ if (ret) return ret; @@ -191,8 +210,11 @@ static int amba_probe(struct device *dev) pm_runtime_enable(dev); ret = pcdrv->probe(pcdev, id); - if (ret == 0) + if (ret == 0) { + if (pm_runtime_is_irq_safe(dev)) + pcdev->irq_safe = 1; break; + } pm_runtime_disable(dev); pm_runtime_set_suspended(dev); diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h index ad52027a9cbf..ce101e4497d6 100644 --- a/include/linux/amba/bus.h +++ b/include/linux/amba/bus.h @@ -32,6 +32,7 @@ struct amba_device { struct clk *pclk; unsigned int periphid; unsigned int irq[AMBA_NR_IRQS]; + unsigned int irq_safe:1; }; struct amba_driver {
The AMBA bus driver defines runtime Power Management functions which disable and unprepare AMBA bus clock. This is problematic for runtime PM because unpreparing a clock might sleep so it is not interrupt safe. However some drivers may want to implement runtime PM functions in interrupt-safe way (see pm_runtime_irq_safe()). In such case the AMBA bus driver should not unprepare/prepare the clock in runtime suspend and resume callbacks. Detect the device driver behavior after calling its probe function and store it. During runtime suspend/resume deal with clocks according to stored value. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> --- drivers/amba/bus.c | 30 ++++++++++++++++++++++++++---- include/linux/amba/bus.h | 1 + 2 files changed, 27 insertions(+), 4 deletions(-)