[PATCH 3/5] ASoC: dwc: Fix channels_max derived from COMP_PARAM_1

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

The I2S_TX_CHANNELS (bits 10:9) and I2S_RX_CHANNELS (bits 8:7) fields
of I2S_COMP_PARAM_1 encode the number of hardware channels minus one,
i.e. values 0..3 mean 1..4 channels. In I2S mode each hardware channel
is one serial data line carrying a left/right pair, so the maximum
number of audio channels is 2 * (N + 1).

The current code uses 1 << (N + 1), which only produces the correct
result for N < 2. For N >= 2, it overestimates the maximum number of
audio channels.

Use 2 * (N + 1) for both playback and capture.

Fixes: b226efe5818b ("ASoC: dwc: Read I2S block configuration from registers")
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---
 sound/soc/dwc/dwc-i2s.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/dwc/dwc-i2s.c b/sound/soc/dwc/dwc-i2s.c
index 6dc84c55db0f..0de7bcb2d0c5 100644
--- a/sound/soc/dwc/dwc-i2s.c
+++ b/sound/soc/dwc/dwc-i2s.c
@@ -605,7 +605,7 @@ static int dw_configure_dai(struct dw_i2s_dev *dev,
 			idx = 1;
 		dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
 		dw_i2s_dai->playback.channels_max =
-				1 << (COMP1_TX_CHANNELS(comp1) + 1);
+				2 * (COMP1_TX_CHANNELS(comp1) + 1);
 		dw_i2s_dai->playback.formats = formats[idx];
 		dw_i2s_dai->playback.rates = rates;
 	}
@@ -619,7 +619,7 @@ static int dw_configure_dai(struct dw_i2s_dev *dev,
 			idx = 1;
 		dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
 		dw_i2s_dai->capture.channels_max =
-				1 << (COMP1_RX_CHANNELS(comp1) + 1);
+				2 * (COMP1_RX_CHANNELS(comp1) + 1);
 		dw_i2s_dai->capture.formats = formats[idx];
 		dw_i2s_dai->capture.rates = rates;
 	}
-- 
2.43.0