[PATCH 3/6] dma: dw: improve comparison with ~0

From: Andy Shevchenko
Date: Mon Jul 15 2013 - 08:05:23 EST


In general ~0 does not fit some integer types. Let's do a helper to make a
comparison with that constant properly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/dma/dw/core.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index bd6b0de..a0aa6f9 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -37,16 +37,22 @@
* 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) {
- dwc->src_master = min_t(unsigned char, mmax, dwc_get_sms(dws));
- dwc->dst_master = min_t(unsigned char, mmax, dwc_get_dms(dws));
- }
+ 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) ({ \
@@ -984,7 +990,7 @@ set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
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);
--
1.8.3.2

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