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NFC: pn533: Don't use out_frame in pn533_send_ack

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

Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Waldemar Rymarkiewicz 2012-12-10 14:42:56 +01:00 committed by Samuel Ortiz
parent fcfafc7690
commit 5b5a4437ae
1 changed files with 6 additions and 25 deletions
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31
drivers/nfc/pn533.c
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@ -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;