Thread (21 messages) 21 messages, 4 authors, 2014-09-25

Re: [PATCH v5 4/4] gpio: add support for the Diolan DLN-2 USB GPIO driver

From: Octavian Purdila <hidden>
Date: 2014-09-20 06:32:27
Also in: linux-i2c, lkml

On Sat, Sep 20, 2014 at 5:48 AM, Arnd Bergmann [off-list ref] wrote:
On Friday 19 September 2014, Octavian Purdila wrote:
quoted
+struct dln2_gpio_pin {
+     __le16 pin;
+} __packed;
This does not need to be marked packed, since it is never embedded in another
structure.
Will do.
quoted
+struct dln2_gpio_pin_val {
+     __le16 pin;
+     u8 value;
+} __packed;
It's enough here to mark just the 'pin' member as packed.
OK.
quoted
+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.
dln2_transfer allocate a new buffer (in dln2_prep_buf(), with
kmalloc()) and does the USB transfer with that buffer.
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