[PATCH stable-6.10 regression] Revert "soundwire: stream: fix programming slave ports for non-continous port maps"

From: Peter Ujfalusi
Date: Tue Sep 10 2024 - 08:40:15 EST


The prop->src_dpn_prop and prop.sink_dpn_prop is allocated for the _number_
of ports and it is forced as 0 index based.

The original code was correct while the change to walk the bits and use
their position as index into the arrays is not correct.

For exmple we can have the prop.source_ports=0x2, which means we have one
port, but the prop.src_dpn_prop[1] is accessing outside of the allocated
memory.

This reverts commit 6fa78e9c41471fe43052cd6feba6eae1b0277ae3.

Cc: stable@xxxxxxxxxxxxxxx # 6.10.y
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxxxxxxxx>
---
Hi,

The reverted patch causes major regression on soundwire causing all audio
to fail.
Interestingly the patch is only in 6.10.8 and 6.10.9, not in mainline or linux-next.

soundwire sdw-master-0-1: Program transport params failed: -22
soundwire sdw-master-0-1: Program params failed: -22
SDW1-Playback: ASoC: error at snd_soc_link_prepare on SDW1-Playback: -22

Regards,
Peter

drivers/soundwire/stream.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 00191b1d2260..4e9e7d2a942d 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -1286,18 +1286,18 @@ struct sdw_dpn_prop *sdw_get_slave_dpn_prop(struct sdw_slave *slave,
unsigned int port_num)
{
struct sdw_dpn_prop *dpn_prop;
- unsigned long mask;
+ u8 num_ports;
int i;

if (direction == SDW_DATA_DIR_TX) {
- mask = slave->prop.source_ports;
+ num_ports = hweight32(slave->prop.source_ports);
dpn_prop = slave->prop.src_dpn_prop;
} else {
- mask = slave->prop.sink_ports;
+ num_ports = hweight32(slave->prop.sink_ports);
dpn_prop = slave->prop.sink_dpn_prop;
}

- for_each_set_bit(i, &mask, 32) {
+ for (i = 0; i < num_ports; i++) {
if (dpn_prop[i].num == port_num)
return &dpn_prop[i];
}
--
2.46.0