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Subject[PATCH 1/2] media: vidtv: cleanup the logic which estimates buffer size
Date
There's no need to use u64 over there. In a matter of fact,
the div is not even needed, as it is multiplying by 1000 and
dividing by 1000.

So, simplify the logic.

While here, constrain the buffer size to a certain range
(between the current value and 10 times it)

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
.../media/test-drivers/vidtv/vidtv_bridge.c | 20 ++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/media/test-drivers/vidtv/vidtv_bridge.c b/drivers/media/test-drivers/vidtv/vidtv_bridge.c
index fe4e496acc34..74b054947bbe 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_bridge.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_bridge.c
@@ -106,26 +106,28 @@ static unsigned int mux_buf_sz_pkts;
module_param(mux_buf_sz_pkts, uint, 0);
MODULE_PARM_DESC(mux_buf_sz_pkts, "Size for the internal mux buffer in multiples of 188 bytes");

+#define MUX_BUF_MIN_SZ 90164
+#define MUX_BUF_MAX_SZ (MUX_BUF_MIN_SZ * 10)
+
static u32 vidtv_bridge_mux_buf_sz_for_mux_rate(void)
{
- u64 max_elapsed_time_msecs = VIDTV_MAX_SLEEP_USECS / 1000;
+ u32 max_elapsed_time_msecs = VIDTV_MAX_SLEEP_USECS / USEC_PER_MSEC;
u32 nbytes_expected;
u32 mux_buf_sz = mux_buf_sz_pkts * TS_PACKET_LEN;
- u32 slack;

- nbytes_expected = div64_u64(mux_rate_kbytes_sec * 1000, MSEC_PER_SEC);
+ nbytes_expected = mux_rate_kbytes_sec;
nbytes_expected *= max_elapsed_time_msecs;

mux_buf_sz = roundup(nbytes_expected, TS_PACKET_LEN);
- slack = mux_buf_sz / 10;
+ mux_buf_sz += mux_buf_sz / 10;

- //if (mux_buf_sz < MUX_BUF_MIN_SZ)
- // mux_buf_sz = MUX_BUF_MIN_SZ;
+ if (mux_buf_sz < MUX_BUF_MIN_SZ)
+ mux_buf_sz = MUX_BUF_MIN_SZ;

- //if (mux_buf_sz > MUX_BUF_MAX_SZ)
- // mux_buf_sz = MUX_BUF_MAX_SZ;
+ if (mux_buf_sz > MUX_BUF_MAX_SZ)
+ mux_buf_sz = MUX_BUF_MAX_SZ;

- return mux_buf_sz + slack;
+ return mux_buf_sz;
}

static bool vidtv_bridge_check_demod_lock(struct vidtv_dvb *dvb, u32 n)
--
2.26.2
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