Re: [PATCH v3 2/2] iio: twl6030-gpadc: TWL6030, TWL6032 GPADC driver

[Oleksandr Kozaruk <oleksandr.kozaruk-l0cyMroinI0@public.gmane.org>]

On Mon, Jul 15, 2013 at 01:33:53PM +0200, Lars-Peter Clausen wrote:
 > On 07/15/2013 01:09 PM, Kozaruk, Oleksandr wrote:
 > [...]
 > >
 > >>> +     ret = devm_request_threaded_irq(dev, irq, NULL,
 > >>> + twl6030_gpadc_irq_handler,
 > >>> + IRQF_ONESHOT, "twl6030_gpadc", gpadc);
 > >>
 > >> You access memory in the interrupt handler which is freed before 
the interrupt
 > >> handler is freed.
 > > Thanks for pointing this. devm_* will free memory for irq after the 
driver
 > > is removed and memory for the device is freed. I took me awhile to 
understand
 > > this. Is there going to be something like devm_iio_device_alloc? 
whould it be helpfull?
 > >
 >
 > Yes, I think it certainly makes sense to add a 
devm_iio_device_alloc(), care
 > to send a patch?

Anything like this? (of course it's not a patch)

struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
{
     struct iio_dev *indio_dev;
     size_t alloc_size;

     alloc_size = sizeof(struct iio_dev);
     if (sizeof_priv) {
         alloc_size = ALIGN(alloc_size, IIO_ALIGN);
         alloc_size += sizeof_priv;
     }
     /* ensure 32-byte alignment of whole construct ? */
     alloc_size += IIO_ALIGN - 1;

     indio_dev = devm_kzalloc(dev, alloc_size, GFP_KERNEL);
     if (indio_dev) {
         indio_dev->dev.groups = indio_dev->groups;
         indio_dev->dev.type = &iio_device_type;
         indio_dev->dev.bus = &iio_bus_type;
         device_initialize(&indio_dev->dev);
         dev_set_drvdata(&indio_dev->dev, (void *)indio_dev);
         mutex_init(&indio_dev->mlock);
         mutex_init(&indio_dev->info_exist_lock);
         INIT_LIST_HEAD(&indio_dev->channel_attr_list);

         indio_dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
         if (indio_dev->id < 0) {
             /* cannot use a dev_err as the name isn't available */
             printk(KERN_ERR "Failed to get id\n");
             kfree(dev);
             return NULL;
         }
         dev_set_name(&indio_dev->dev, "iio:device%d", indio_dev->id);
         INIT_LIST_HEAD(&indio_dev->buffer_list);
     }

     return indio_dev;
}
EXPORT_SYMBOL(devm_iio_device_alloc);

Regards,
OK