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[v3,17/23] counter: intel-qep: Convert to new counter registration

Message ID 20211229154441.38045-18-u.kleine-koenig@pengutronix.de (mailing list archive)
State Handled Elsewhere
Headers show
Series counter: cleanups and device lifetime fixes | expand

Commit Message

Uwe Kleine-König Dec. 29, 2021, 3:44 p.m. UTC
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: b711f687a1c1 ("counter: Add support for Intel Quadrature Encoder Peripheral")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/counter/intel-qep.c | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

Comments

Jarkko Nikula Dec. 30, 2021, 10:26 a.m. UTC | #1
On 12/29/21 17:44, Uwe Kleine-König wrote:
> This fixes device lifetime issues where it was possible to free a live
> struct device.
> 
> Fixes: b711f687a1c1 ("counter: Add support for Intel Quadrature Encoder Peripheral")
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>   drivers/counter/intel-qep.c | 28 ++++++++++++++++------------
>   1 file changed, 16 insertions(+), 12 deletions(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Following test will cause an oops usually after a few iterations before 
this patch:

while :; do { sleep 5; echo bang; } > /dev/counter0 & sleep 1; echo 
0000:00:18.4 >/sys/bus/pci/drivers/intel-qep/unbind; sleep 8; echo 
0000:00:18.4 >/sys/bus/pci/drivers/intel-qep/bind; done
diff mbox series

Patch

diff --git a/drivers/counter/intel-qep.c b/drivers/counter/intel-qep.c
index 8f84a48508ac..47a6a9dfc9e8 100644
--- a/drivers/counter/intel-qep.c
+++ b/drivers/counter/intel-qep.c
@@ -63,7 +63,6 @@ 
 #define INTEL_QEP_CLK_PERIOD_NS		10
 
 struct intel_qep {
-	struct counter_device counter;
 	struct mutex lock;
 	struct device *dev;
 	void __iomem *regs;
@@ -392,14 +391,16 @@  static struct counter_count intel_qep_counter_count[] = {
 
 static int intel_qep_probe(struct pci_dev *pci, const struct pci_device_id *id)
 {
+	struct counter_device *counter;
 	struct intel_qep *qep;
 	struct device *dev = &pci->dev;
 	void __iomem *regs;
 	int ret;
 
-	qep = devm_kzalloc(dev, sizeof(*qep), GFP_KERNEL);
-	if (!qep)
+	counter = devm_counter_alloc(dev, sizeof(*qep));
+	if (!counter)
 		return -ENOMEM;
+	qep = counter_priv(counter);
 
 	ret = pcim_enable_device(pci);
 	if (ret)
@@ -422,20 +423,23 @@  static int intel_qep_probe(struct pci_dev *pci, const struct pci_device_id *id)
 	intel_qep_init(qep);
 	pci_set_drvdata(pci, qep);
 
-	qep->counter.name = pci_name(pci);
-	qep->counter.parent = dev;
-	qep->counter.ops = &intel_qep_counter_ops;
-	qep->counter.counts = intel_qep_counter_count;
-	qep->counter.num_counts = ARRAY_SIZE(intel_qep_counter_count);
-	qep->counter.signals = intel_qep_signals;
-	qep->counter.num_signals = ARRAY_SIZE(intel_qep_signals);
-	qep->counter.priv = qep;
+	counter->name = pci_name(pci);
+	counter->parent = dev;
+	counter->ops = &intel_qep_counter_ops;
+	counter->counts = intel_qep_counter_count;
+	counter->num_counts = ARRAY_SIZE(intel_qep_counter_count);
+	counter->signals = intel_qep_signals;
+	counter->num_signals = ARRAY_SIZE(intel_qep_signals);
 	qep->enabled = false;
 
 	pm_runtime_put(dev);
 	pm_runtime_allow(dev);
 
-	return devm_counter_register(&pci->dev, &qep->counter);
+	ret = devm_counter_add(&pci->dev, counter);
+	if (ret < 0)
+		return dev_err_probe(&pci->dev, ret, "Failed to add counter\n");
+
+	return 0;
 }
 
 static void intel_qep_remove(struct pci_dev *pci)