2021-12-29 15:45:46

by Uwe Kleine-König

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

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 <[email protected]>
Acked-by: William Breathitt Gray <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
---
drivers/counter/intel-qep.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)

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)
--
2.34.1

2021-12-30 10:26:47

by Jarkko Nikula

Subject: Re: [PATCH v3 17/23] counter: intel-qep: Convert to new counter registration

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 <[email protected]>
> Acked-by: William Breathitt Gray <[email protected]>
> Signed-off-by: Uwe Kleine-König <[email protected]>
> ---
> drivers/counter/intel-qep.c | 28 ++++++++++++++++------------
> 1 file changed, 16 insertions(+), 12 deletions(-)
>
Acked-by: Jarkko Nikula <[email protected]>
Tested-by: Jarkko Nikula <[email protected]>

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