[PATCH v2 11/19] [media] ddbridge: fix output buffer check

[Daniel Scheller]

From: Daniel Scheller <d.schel...@gmx.net>

A 188 byte gap has to be left between the writer and the consumer. This
requires 2*188 bytes available to be able to write to the output buffers.
So, change ddb_output_free() to report free bytes according to this rule.

Picked up from the upstream dddvb-0.9.33 release.

Signed-off-by: Daniel Scheller <d.schel...@gmx.net>
---
 drivers/media/pci/ddbridge/ddbridge-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/pci/ddbridge/ddbridge-core.c 
b/drivers/media/pci/ddbridge/ddbridge-core.c
index c22537eceee5..e9c2e3e5d64b 100644
--- a/drivers/media/pci/ddbridge/ddbridge-core.c
+++ b/drivers/media/pci/ddbridge/ddbridge-core.c
@@ -587,12 +587,12 @@ static u32 ddb_output_free(struct ddb_output *output)
 
        if (output->dma->cbuf != idx) {
                if ((((output->dma->cbuf + 1) % output->dma->num) == idx) &&
-                   (output->dma->size - output->dma->coff <= 188))
+                   (output->dma->size - output->dma->coff <= (2 * 188)))
                        return 0;
                return 188;
        }
        diff = off - output->dma->coff;
-       if (diff <= 0 || diff > 188)
+       if (diff <= 0 || diff > (2 * 188))
                return 188;
        return 0;
 }
-- 
2.16.1