2015-12-13 08:04:46

by Saurabh Sengar

Subject: [RESEND PATCH] NFC: added the sysfs entry for nfcsim workqueue delay

added the sysfs entry for nfcsim workqueue delay, as tx_delay

Signed-off-by: Saurabh Sengar <[email protected]>
---
In case this TODO is not expected to be done, please let me know.
I wonder after my repeated attempts since last 50 days, I am not able to get a single response.
Resending this patch in hope to get some response this time.

drivers/nfc/nfcsim.c | 38 +++++++++++++++++++++++++++++++++++---
1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/nfcsim.c b/drivers/nfc/nfcsim.c
index 26ac9e5..e77be35 100644
--- a/drivers/nfc/nfcsim.c
+++ b/drivers/nfc/nfcsim.c
@@ -32,6 +32,8 @@
#define NFCSIM_POLL_TARGET 2
#define NFCSIM_POLL_DUAL (NFCSIM_POLL_INITIATOR | NFCSIM_POLL_TARGET)

+#define TX_DEFAULT_DELAY 5
+
struct nfcsim {
struct nfc_dev *nfc_dev;

@@ -62,12 +64,41 @@ static struct nfcsim *dev1;

static struct workqueue_struct *wq;

+
+static int tx_delay = TX_DEFAULT_DELAY;
+
+static ssize_t show_tx_delay(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int n;
+
+ n = scnprintf(buf, PAGE_SIZE, "%d\n", tx_delay);
+ return n;
+}
+
+static ssize_t store_tx_delay(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ if (kstrtouint(buf, 0, &tx_delay) < 0)
+ return -EINVAL;
+
+ if (tx_delay < 0)
+ return -EINVAL;
+
+ return count;
+}
+
+static DEVICE_ATTR(tx_delay, 0644, show_tx_delay, store_tx_delay);
+
static void nfcsim_cleanup_dev(struct nfcsim *dev, u8 shutdown)
{
DEV_DBG(dev, "shutdown=%d\n", shutdown);

mutex_lock(&dev->lock);

+ device_remove_file(&dev->nfc_dev->dev, &dev_attr_tx_delay);
dev->polling_mode = NFCSIM_POLL_NONE;
dev->shutting_down = shutdown;
dev->cb = NULL;
@@ -320,10 +351,8 @@ static int nfcsim_tx(struct nfc_dev *nfc_dev, struct nfc_target *target,
* If packet transmission occurs immediately between them, we have a
* non-stop flow of several tens of thousands SYMM packets per second
* and a burning cpu.
- *
- * TODO: Add support for a sysfs entry to control this delay.
*/
- queue_delayed_work(wq, &peer->recv_work, msecs_to_jiffies(5));
+ queue_delayed_work(wq, &peer->recv_work, msecs_to_jiffies(tx_delay));

mutex_unlock(&peer->lock);

@@ -461,6 +490,9 @@ static struct nfcsim *nfcsim_init_dev(void)
if (rc)
goto free_nfc_dev;

+ rc = device_create_file(&dev->nfc_dev->dev, &dev_attr_tx_delay);
+ if (rc)
+ pr_err("error creating sysfs entry\n");
return dev;

free_nfc_dev:
--
1.9.1

2015-12-20 17:50:44

by Samuel Ortiz

Subject: Re: [RESEND PATCH] NFC: added the sysfs entry for nfcsim workqueue delay

Hi Saurabh,

On Sun, Dec 13, 2015 at 01:34:35PM +0530, Saurabh Sengar wrote:
> added the sysfs entry for nfcsim workqueue delay, as tx_delay
>
> Signed-off-by: Saurabh Sengar <[email protected]>
> ---
> In case this TODO is not expected to be done, please let me know.
> I wonder after my repeated attempts since last 50 days, I am not able to get a single response.
Apologies for the delay.


> Resending this patch in hope to get some response this time.
>
> drivers/nfc/nfcsim.c | 38 +++++++++++++++++++++++++++++++++++---
> 1 file changed, 35 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nfc/nfcsim.c b/drivers/nfc/nfcsim.c
> index 26ac9e5..e77be35 100644
> --- a/drivers/nfc/nfcsim.c
> +++ b/drivers/nfc/nfcsim.c
> @@ -32,6 +32,8 @@
> #define NFCSIM_POLL_TARGET 2
> #define NFCSIM_POLL_DUAL (NFCSIM_POLL_INITIATOR | NFCSIM_POLL_TARGET)
>
> +#define TX_DEFAULT_DELAY 5
> +
> struct nfcsim {
> struct nfc_dev *nfc_dev;
>
> @@ -62,12 +64,41 @@ static struct nfcsim *dev1;
>
> static struct workqueue_struct *wq;
>
> +
> +static int tx_delay = TX_DEFAULT_DELAY;
2 things:

- This actually defines an rx delay as it delays the start of the
receiving workqueue, so the name should be tx_*. I'm being picky here,
because with this special driver an Rx delay is implicitely a Tx
one.
- I'd prefer this to be tunable by device, so it should be defined as an
additional field in the nfcsim structure (rx_delay ?) and set by default
to RX_DEFAULT_DELAY from nfcsim_init_dev.

Cheers,
Samuel.