Re: [PATCH v2] watchdog: ziirave_wdt: Add support to upload the firmware.

From: Guenter Roeck
Date: Thu Jul 21 2016 - 09:25:11 EST

On 07/21/2016 01:59 AM, Enric Balletbo Serra wrote:

[ ... ]

+static ssize_t ziirave_wdt_sysfs_store_firm(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
+ const struct firmware *fw;
+ int err;

What happens if this file is opened twice and written in parallel ?
What if any
other attribute is accessed while the firmware download is ongoing ?

Good point. So you think I need to protect all with mutexes or there

Yes, you have to protect any possible damaging parallel access with mutexes.

is another way? From a quick look on other drivers i didn't see this
kind of protection (something to look at in the future)

Really ? Can you point me to some examples ? This would be a bug.

You'll have to fix the to get your patch accepted. Pointing to other
examples with the same or a similar bug is not an argument.