[PATCH] Input: rmi4 - remove the need for artificial IRQ in case of HID

From: Benjamin Tissoires
Date: Mon Apr 03 2017 - 12:18:38 EST


The IRQ from rmi4 may interfere with the one we currently use on i2c-hid.
Given that there is already a need for an external API from rmi4 to
forward the attention data, we can, in this particular case rely on a
separate workqueue to prevent cursor jumps.

Reported-by: Cameron Gutman <aicommander@xxxxxxxxx>
Reported-by: Thorsten Leemhuis <linux@xxxxxxxxxxxxx>
Reported-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
Tested-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---

Hi Dmitry, Jiri,

This is a regression introduced by my code in v4.11.
I do not think it is worth splitting between HID and input, there hasn't
been any development in hid-rmi since v4.11-rc1.

Cheers,
Benjamin

drivers/hid/hid-rmi.c | 64 ---------------------
drivers/input/rmi4/rmi_driver.c | 122 ++++++++++++++++++++++++----------------
include/linux/rmi.h | 1 +
3 files changed, 75 insertions(+), 112 deletions(-)

diff --git a/drivers/hid/hid-rmi.c b/drivers/hid/hid-rmi.c
index 5b40c26..4aa882c 100644
--- a/drivers/hid/hid-rmi.c
+++ b/drivers/hid/hid-rmi.c
@@ -316,19 +316,12 @@ static int rmi_input_event(struct hid_device *hdev, u8 *data, int size)
{
struct rmi_data *hdata = hid_get_drvdata(hdev);
struct rmi_device *rmi_dev = hdata->xport.rmi_dev;
- unsigned long flags;

if (!(test_bit(RMI_STARTED, &hdata->flags)))
return 0;

- local_irq_save(flags);
-
rmi_set_attn_data(rmi_dev, data[1], &data[2], size - 2);

- generic_handle_irq(hdata->rmi_irq);
-
- local_irq_restore(flags);
-
return 1;
}

@@ -556,56 +549,6 @@ static const struct rmi_transport_ops hid_rmi_ops = {
.reset = rmi_hid_reset,
};

-static void rmi_irq_teardown(void *data)
-{
- struct rmi_data *hdata = data;
- struct irq_domain *domain = hdata->domain;
-
- if (!domain)
- return;
-
- irq_dispose_mapping(irq_find_mapping(domain, 0));
-
- irq_domain_remove(domain);
- hdata->domain = NULL;
- hdata->rmi_irq = 0;
-}
-
-static int rmi_irq_map(struct irq_domain *h, unsigned int virq,
- irq_hw_number_t hw_irq_num)
-{
- irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
-
- return 0;
-}
-
-static const struct irq_domain_ops rmi_irq_ops = {
- .map = rmi_irq_map,
-};
-
-static int rmi_setup_irq_domain(struct hid_device *hdev)
-{
- struct rmi_data *hdata = hid_get_drvdata(hdev);
- int ret;
-
- hdata->domain = irq_domain_create_linear(hdev->dev.fwnode, 1,
- &rmi_irq_ops, hdata);
- if (!hdata->domain)
- return -ENOMEM;
-
- ret = devm_add_action_or_reset(&hdev->dev, &rmi_irq_teardown, hdata);
- if (ret)
- return ret;
-
- hdata->rmi_irq = irq_create_mapping(hdata->domain, 0);
- if (hdata->rmi_irq <= 0) {
- hid_err(hdev, "Can't allocate an IRQ\n");
- return hdata->rmi_irq < 0 ? hdata->rmi_irq : -ENXIO;
- }
-
- return 0;
-}
-
static int rmi_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
struct rmi_data *data = NULL;
@@ -677,18 +620,11 @@ static int rmi_probe(struct hid_device *hdev, const struct hid_device_id *id)

mutex_init(&data->page_mutex);

- ret = rmi_setup_irq_domain(hdev);
- if (ret) {
- hid_err(hdev, "failed to allocate IRQ domain\n");
- return ret;
- }
-
if (data->device_flags & RMI_DEVICE_HAS_PHYS_BUTTONS)
rmi_hid_pdata.f30_data.disable = true;

data->xport.dev = hdev->dev.parent;
data->xport.pdata = rmi_hid_pdata;
- data->xport.pdata.irq = data->rmi_irq;
data->xport.proto_name = "hid";
data->xport.ops = &hid_rmi_ops;

diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
index d64fc92..5e65cba 100644
--- a/drivers/input/rmi4/rmi_driver.c
+++ b/drivers/input/rmi4/rmi_driver.c
@@ -209,32 +209,46 @@ void rmi_set_attn_data(struct rmi_device *rmi_dev, unsigned long irq_status,
attn_data.data = fifo_data;

kfifo_put(&drvdata->attn_fifo, attn_data);
+
+ schedule_work(&drvdata->attn_work);
}
EXPORT_SYMBOL_GPL(rmi_set_attn_data);

-static irqreturn_t rmi_irq_fn(int irq, void *dev_id)
+static void attn_callback(struct work_struct *work)
{
- struct rmi_device *rmi_dev = dev_id;
- struct rmi_driver_data *drvdata = dev_get_drvdata(&rmi_dev->dev);
+ struct rmi_driver_data *drvdata = container_of(work,
+ struct rmi_driver_data,
+ attn_work);
struct rmi4_attn_data attn_data = {0};
int ret, count;

count = kfifo_get(&drvdata->attn_fifo, &attn_data);
- if (count) {
- *(drvdata->irq_status) = attn_data.irq_status;
- drvdata->attn_data = attn_data;
- }
+ if (!count)
+ return;

- ret = rmi_process_interrupt_requests(rmi_dev);
+ *(drvdata->irq_status) = attn_data.irq_status;
+ drvdata->attn_data = attn_data;
+
+ ret = rmi_process_interrupt_requests(drvdata->rmi_dev);
if (ret)
- rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev,
+ rmi_dbg(RMI_DEBUG_CORE, &drvdata->rmi_dev->dev,
"Failed to process interrupt request: %d\n", ret);

- if (count)
- kfree(attn_data.data);
+ kfree(attn_data.data);

if (!kfifo_is_empty(&drvdata->attn_fifo))
- return rmi_irq_fn(irq, dev_id);
+ schedule_work(&drvdata->attn_work);
+}
+
+static irqreturn_t rmi_irq_fn(int irq, void *dev_id)
+{
+ struct rmi_device *rmi_dev = dev_id;
+ int ret;
+
+ ret = rmi_process_interrupt_requests(rmi_dev);
+ if (ret)
+ rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev,
+ "Failed to process interrupt request: %d\n", ret);

return IRQ_HANDLED;
}
@@ -242,7 +256,6 @@ static irqreturn_t rmi_irq_fn(int irq, void *dev_id)
static int rmi_irq_init(struct rmi_device *rmi_dev)
{
struct rmi_device_platform_data *pdata = rmi_get_platform_data(rmi_dev);
- struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);
int irq_flags = irq_get_trigger_type(pdata->irq);
int ret;

@@ -260,8 +273,6 @@ static int rmi_irq_init(struct rmi_device *rmi_dev)
return ret;
}

- data->enabled = true;
-
return 0;
}

@@ -910,23 +921,27 @@ void rmi_enable_irq(struct rmi_device *rmi_dev, bool clear_wake)
if (data->enabled)
goto out;

- enable_irq(irq);
- data->enabled = true;
- if (clear_wake && device_may_wakeup(rmi_dev->xport->dev)) {
- retval = disable_irq_wake(irq);
- if (retval)
- dev_warn(&rmi_dev->dev,
- "Failed to disable irq for wake: %d\n",
- retval);
- }
+ if (irq) {
+ enable_irq(irq);
+ data->enabled = true;
+ if (clear_wake && device_may_wakeup(rmi_dev->xport->dev)) {
+ retval = disable_irq_wake(irq);
+ if (retval)
+ dev_warn(&rmi_dev->dev,
+ "Failed to disable irq for wake: %d\n",
+ retval);
+ }

- /*
- * Call rmi_process_interrupt_requests() after enabling irq,
- * otherwise we may lose interrupt on edge-triggered systems.
- */
- irq_flags = irq_get_trigger_type(pdata->irq);
- if (irq_flags & IRQ_TYPE_EDGE_BOTH)
- rmi_process_interrupt_requests(rmi_dev);
+ /*
+ * Call rmi_process_interrupt_requests() after enabling irq,
+ * otherwise we may lose interrupt on edge-triggered systems.
+ */
+ irq_flags = irq_get_trigger_type(pdata->irq);
+ if (irq_flags & IRQ_TYPE_EDGE_BOTH)
+ rmi_process_interrupt_requests(rmi_dev);
+ } else {
+ data->enabled = true;
+ }

out:
mutex_unlock(&data->enabled_mutex);
@@ -946,20 +961,22 @@ void rmi_disable_irq(struct rmi_device *rmi_dev, bool enable_wake)
goto out;

data->enabled = false;
- disable_irq(irq);
- if (enable_wake && device_may_wakeup(rmi_dev->xport->dev)) {
- retval = enable_irq_wake(irq);
- if (retval)
- dev_warn(&rmi_dev->dev,
- "Failed to enable irq for wake: %d\n",
- retval);
- }
-
- /* make sure the fifo is clean */
- while (!kfifo_is_empty(&data->attn_fifo)) {
- count = kfifo_get(&data->attn_fifo, &attn_data);
- if (count)
- kfree(attn_data.data);
+ if (irq) {
+ disable_irq(irq);
+ if (enable_wake && device_may_wakeup(rmi_dev->xport->dev)) {
+ retval = enable_irq_wake(irq);
+ if (retval)
+ dev_warn(&rmi_dev->dev,
+ "Failed to enable irq for wake: %d\n",
+ retval);
+ }
+ } else {
+ /* make sure the fifo is clean */
+ while (!kfifo_is_empty(&data->attn_fifo)) {
+ count = kfifo_get(&data->attn_fifo, &attn_data);
+ if (count)
+ kfree(attn_data.data);
+ }
}

out:
@@ -998,9 +1015,12 @@ EXPORT_SYMBOL_GPL(rmi_driver_resume);
static int rmi_driver_remove(struct device *dev)
{
struct rmi_device *rmi_dev = to_rmi_device(dev);
+ struct rmi_driver_data *data = dev_get_drvdata(&rmi_dev->dev);

rmi_disable_irq(rmi_dev, false);

+ cancel_work_sync(&data->attn_work);
+
rmi_f34_remove_sysfs(rmi_dev);
rmi_free_function_list(rmi_dev);

@@ -1230,9 +1250,15 @@ static int rmi_driver_probe(struct device *dev)
}
}

- retval = rmi_irq_init(rmi_dev);
- if (retval < 0)
- goto err_destroy_functions;
+ if (pdata->irq) {
+ retval = rmi_irq_init(rmi_dev);
+ if (retval < 0)
+ goto err_destroy_functions;
+ }
+
+ data->enabled = true;
+
+ INIT_WORK(&data->attn_work, attn_callback);

if (data->f01_container->dev.driver)
/* Driver already bound, so enable ATTN now. */
diff --git a/include/linux/rmi.h b/include/linux/rmi.h
index 64125443..dc90178 100644
--- a/include/linux/rmi.h
+++ b/include/linux/rmi.h
@@ -364,6 +364,7 @@ struct rmi_driver_data {

struct rmi4_attn_data attn_data;
DECLARE_KFIFO(attn_fifo, struct rmi4_attn_data, 16);
+ struct work_struct attn_work;
};

int rmi_register_transport_device(struct rmi_transport_dev *xport);
--
2.9.3