On 12/18/2013 06:39 AM, Dmitry Torokhov wrote:
Hi Chris,
On Tue, Dec 17, 2013 at 12:16:01PM -0800, Christopher Heiny wrote:
This patch fixes two bugs in handling of the RMI4 attention line GPIO.
1) in enable_sensor(), make sure the attn_gpio is defined before attempting to
get its value.
2) in rmi_driver_probe(), declare the name of the attn_gpio, then
request the attn_gpio before attempting to export it.
Also introduces a GPIO_LABEL constant for identifying the attention GPIO.
I was looking at the patch some more and I have some concerns with it.
Signed-off-by: Christopher Heiny <cheiny@xxxxxxxxxxxxx>
Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/input/rmi4/rmi_driver.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
index a30c7d3..33fb8f8 100644
--- a/drivers/input/rmi4/rmi_driver.c
+++ b/drivers/input/rmi4/rmi_driver.c
@@ -169,7 +169,7 @@ static int enable_sensor(struct rmi_device *rmi_dev)
data->enabled = true;
- if (!pdata->level_triggered &&
+ if (pdata->attn_gpio && !pdata->level_triggered &&
O is perfectly fine GPIO number, you want to use gpio_is_valid() hete. I
also wonder why do you need such elaborate check. Can we simply "flush"
device before enabling interrupts?
Hmmm. gpio_is_valid() is a good suggestion. However, I think we can do
away with the whole check on the ATTN gpio, and just call
process_interrupt_requests(). That will both flush the state and handle
any important pending events. In the typical use case for
enable_sensor(), the RMI4 device will either be just coming up or else
coming out of a diagnostic mode, and there will at least be a status
event to handle. In the off-case where there is nothing pending (that
is, ATTN not asserted), the overhead is pretty low - just a quick read
of the interrupt status register.
gpio_get_value(pdata->attn_gpio) == pdata->attn_polarity)
retval = process_interrupt_requests(rmi_dev);
@@ -807,6 +807,8 @@ static int rmi_driver_remove(struct device *dev)
return 0;
}
+static const char GPIO_LABEL[] = "attn";
+
static int rmi_driver_probe(struct device *dev)
{
struct rmi_driver *rmi_driver;
@@ -959,20 +961,24 @@ static int rmi_driver_probe(struct device *dev)
}
if (IS_ENABLED(CONFIG_RMI4_DEV) && pdata->attn_gpio) {
- retval = gpio_export(pdata->attn_gpio, false);
+ retval = gpio_request(pdata->attn_gpio, GPIO_LABEL);
Here it is too late to request GPIO. You have been converting it to IRQ,
enabling that IRQ and calling gpio_get_value() so GPIO should have
already been requested by now.
So you need to move this code up.
I'll give that a try.
> You may also consider using
gpio_request_one() and use GPIOF_EXPORT flag if you want to export it.
It would also be nice to set the direction (GPIOF_DIR_IN).
Both of these are good ideas.
I also do not see matching call to gpio_free() in remove().
Neither do I :-(.
We'll update.
if (retval) {
- dev_warn(dev, "WARNING: Failed to export ATTN gpio!\n");
- retval = 0;
+ dev_warn(dev, "WARNING: Failed to request ATTN gpio %d, code: %d.\n",
+ pdata->attn_gpio, retval);
} else {
- retval = gpio_export_link(dev,
- "attn", pdata->attn_gpio);
+ retval = gpio_export(pdata->attn_gpio, false);
if (retval) {
- dev_warn(dev,
- "WARNING: Failed to symlink ATTN gpio!\n");
- retval = 0;
+ dev_warn(dev, "WARNING: Failed to export ATTN gpio %d, code: %d.\n",
+ pdata->attn_gpio, retval);
} else {
- dev_info(dev, "Exported ATTN GPIO %d.",
- pdata->attn_gpio);
+ retval = gpio_export_link(dev, GPIO_LABEL,
+ pdata->attn_gpio);
+ if (retval)
+ dev_warn(dev,
+ "WARNING: Failed to symlink ATTN gpio!\n");
+ else
+ dev_info(dev, "Exported ATTN GPIO %d.",
+ pdata->attn_gpio);
}
}
}
Thanks.
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