dma: dw: improve comparison with ~0

 * which does not support descriptor writeback.

 */

static inline bool is_request_line_unset(struct dw_dma_chan *dwc)

{

	return dwc->request_line == (typeof(dwc->request_line))~0;

}

static inline void dwc_set_masters(struct dw_dma_chan *dwc)

{

	struct dw_dma *dw = to_dw_dma(dwc->chan.device);

	struct dw_dma_slave *dws = dwc->chan.private;

	unsigned char mmax = dw->nr_masters - 1;

	if (dwc->request_line == ~0) {

	if (!is_request_line_unset(dwc))

		return;

	dwc->src_master = min_t(unsigned char, mmax, dwc_get_sms(dws));

	dwc->dst_master = min_t(unsigned char, mmax, dwc_get_dms(dws));

}

}

#define DWC_DEFAULT_CTLLO(_chan) ({				\

		struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan);	\

	dwc->direction = sconfig->direction;

	/* Take the request line from slave_id member */

	if (dwc->request_line == ~0)

	if (is_request_line_unset(dwc))

		dwc->request_line = sconfig->slave_id;

	convert_burst(&dwc->dma_sconfig.src_maxburst);