Re: [PATCH 3/4] cp210x: Store part number

From: Oliver Neukum
Date: Sun Jul 26 2015 - 09:33:59 EST


On Fri, 2015-07-24 at 08:48 +0200, Petr Tesarik wrote:
> @@ -872,6 +886,12 @@ static int cp210x_startup(struct usb_serial
> *serial)
>
> usb_set_serial_data(serial, spriv);
>
> + /* Get the 1-byte part number of the cp210x device */
> + cp210x_control_msg(serial->port[0], CP210X_VENDOR_SPECIFIC,
> + REQTYPE_DEVICE_TO_HOST, CP210X_GET_PARTNUM,
> + &partnum, 1, USB_CTRL_GET_TIMEOUT);
> + spriv->bPartNumber = partnum & 0xFF;

DMA on the stack. That breaks the cache coherency rules.
You must kmalloc the buffer.

Regards
Oliver


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