On Friday 19 September 2014, Octavian Purdila wrote:
> +struct dln2_gpio_pin {
> + __le16 pin;
> +} __packed;
This does not need to be marked packed, since it is never embedded in another
structure.
> +struct dln2_gpio_pin_val {
> + __le16 pin;
> + u8 value;
> +} __packed;
It's enough here to mark just the 'pin' member as packed.
> +static int dln2_gpio_get_pin_count(struct platform_device *pdev)
> +{
> + int ret;
> + __le16 count;
> + int len = sizeof(count);
> +
> + ret = dln2_transfer(pdev, DLN2_GPIO_GET_PIN_COUNT, NULL, 0, &count,
> + &len);
You must not do a USB transaction on stack memory.
> +static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin)
> +{
> + struct dln2_gpio_pin req = {
> + .pin = cpu_to_le16(pin),
> + };
> +
> + return dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), NULL, NULL);
> +}
Same here
> +static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int
> pin)
> +{
> + int ret;
> + struct dln2_gpio_pin req = {
> + .pin = cpu_to_le16(pin),
> + };
> + struct dln2_gpio_pin_val rsp;
And here.
> +static int dln2_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
> + unsigned debounce)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> + struct {
> + __le32 duration;
> + } __packed req = {
> + .duration = cpu_to_le32(debounce),
> + };
> +
> + return dln2_transfer(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE,
> + &req, sizeof(req), NULL, NULL);
> +}
Here you also have a strange __packed attribute that makes no sense
for a local variable, in addition to the stack problem.
I think the only correct way to handle these is to add a dynamic
allocation of an entire page for the DMA, which can probably be
part of the dln2_transfer function so you don't have to do it
in each caller.
Arnd
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