Commit 5b5a4437 authored by Waldemar Rymarkiewicz's avatar Waldemar Rymarkiewicz Committed by Samuel Ortiz
Browse files

NFC: pn533: Don't use out_frame in pn533_send_ack 



dev->out_frame buffer is much bigger for ACK frame needs. Use
local buffer instead.

Signed-off-by: default avatarWaldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent fcfafc76

drivers/nfc/pn533.c

+6 −25
Original line number Diff line number Diff line
@@ -94,7 +94,8 @@ MODULE_DEVICE_TABLE(usb, pn533_table); 


#define PN533_FRAME_SIZE(f) (sizeof(struct pn533_frame) + f->datalen + \

				PN533_FRAME_TAIL_LEN)

#define PN533_FRAME_ACK_SIZE (sizeof(struct pn533_frame) + 1)

#define PN533_FRAME_ACK_SIZE 6 /* Preamble (1), SoPC (2), ACK Code (2),

				  Postamble (1) */

#define PN533_FRAME_CHECKSUM(f) (f->data[f->datalen])

#define PN533_FRAME_POSTAMBLE(f) (f->data[f->datalen + 1])
@@ -402,26 +403,6 @@ static u8 pn533_data_checksum(u8 *data, int datalen) 
	return pn533_checksum(sum);

}



/**

 * pn533_tx_frame_ack - create a ack frame

 * @frame:	The frame to be set as ack

 *

 * Ack is different type of standard frame. As a standard frame, it has

 * preamble and start_frame. However the checksum of this frame must fail,

 * i.e. datalen + datalen_checksum must NOT be zero. When the checksum test

 * fails and datalen = 0 and datalen_checksum = 0xFF, the frame is a ack.

 * After datalen_checksum field, the postamble is placed.

 */

static void pn533_tx_frame_ack(struct pn533_frame *frame)

{

	frame->preamble = 0;

	frame->start_frame = cpu_to_be16(PN533_SOF);

	frame->datalen = 0;

	frame->datalen_checksum = 0xFF;

	/* data[0] is used as postamble */

	frame->data[0] = 0;

}



static void pn533_tx_frame_init(struct pn533_frame *frame, u8 cmd)

{

	frame->preamble = 0;
@@ -612,14 +593,14 @@ static int pn533_submit_urb_for_ack(struct pn533 *dev, gfp_t flags) 


static int pn533_send_ack(struct pn533 *dev, gfp_t flags)

{

	u8 ack[PN533_FRAME_ACK_SIZE] = {0x00, 0x00, 0xff, 0x00, 0xff, 0x00};

	/* spec 7.1.1.3:  Preamble, SoPC (2), ACK Code (2), Postamble */

	int rc;



	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);



	pn533_tx_frame_ack(dev->out_frame);



	dev->out_urb->transfer_buffer = dev->out_frame;

	dev->out_urb->transfer_buffer_length = PN533_FRAME_ACK_SIZE;

	dev->out_urb->transfer_buffer = ack;

	dev->out_urb->transfer_buffer_length = sizeof(ack);

	rc = usb_submit_urb(dev->out_urb, flags);



	return rc;