If NO_DMA=y:
drivers/built-in.o: In function `fbtft_framebuffer_alloc':
(.text+0xb53cae): undefined reference to `dmam_alloc_coherent'
As DMA support is already optional, make it depend on HAS_DMA.
If !HAS_DMA, "dma" will always be false, and the compiler will optimize
away the call to dmam_alloc_coherent().
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
v2:
- Explain better how it works,
- Keep the "= false" to avoid breakage (seen not only with gcc 4.1.2,
but also with 4.6.3 and 4.9.0).
---
drivers/staging/fbtft/fbtft-core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index 53b748be27124793..600dbdcaa716cd76 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -47,9 +47,14 @@ static unsigned long debug;
module_param(debug, ulong, 0);
MODULE_PARM_DESC(debug, "override device debug level");
+#ifdef CONFIG_HAS_DMA
static bool dma = true;
module_param(dma, bool, 0);
MODULE_PARM_DESC(dma, "Use DMA buffer");
+#else
+/* Do not remove the "= false", gcc needs it to optimize away the DMA calls */
+static const bool dma = false;
+#endif
void fbtft_dbg_hex(const struct device *dev, int groupsize,
--
1.9.1
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