The response sent by the firmware when requesting a clock vote (opcode AFE_CMD_RSP_REMOTE_LPASS_CORE_HW_VOTE_REQUEST) does not actually have the same opcode + status payload as APR_BASIC_RSP_RESULT. Rather, it returns one single u32 which is the client_handle that must be used in future unvote requests for the same clock.
As a result of this type confusion, the status returned by the callback to q6afe_vote_lpass_core_hw was actually an out-of-bounds read. It was only interpreted as success (0) most of the time due to luck, but there are some reports of random errors such as: [ 20.961100] qcom-q6afe aprsvc:service:4:4: AFE failed to vote (3) [ 20.961131] Failed to prepare clk 'core': -110 Fix by correctly interpreting the response as a single u32, and actually store it as the client_handle to ensure unvote would work correctly. Cc: [email protected] Link: https://lore.kernel.org/all/5976946.DvuYhMxLoT@antlia/ Fixes: 55e07531d922 ("ASoC: q6dsp: q6afe: add lpass hw voting support") Reviewed-by: Srinivas Kandagatla <[email protected]> Signed-off-by: Val Packett <[email protected]> --- Previously part of a series: https://lore.kernel.org/all/[email protected]/ but it's actually independent and reviewed, let's try again with just this.. Thanks, ~val --- sound/soc/qcom/qdsp6/q6afe.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c index f0ff1350e9dd..9ac51c304ead 100644 --- a/sound/soc/qcom/qdsp6/q6afe.c +++ b/sound/soc/qcom/qdsp6/q6afe.c @@ -393,6 +393,7 @@ struct q6afe { struct q6core_svc_api_info ainfo; struct mutex lock; struct aprv2_ibasic_rsp_result_t result; + uint32_t vote_result; wait_queue_head_t wait; struct list_head port_list; spinlock_t port_list_lock; @@ -1010,13 +1011,14 @@ static int q6afe_callback(struct apr_device *adev, const struct apr_resp_pkt *da const struct aprv2_ibasic_rsp_result_t *res; const struct apr_hdr *hdr = &data->hdr; struct q6afe_port *port; + uint32_t *vote_res; if (!data->payload_size) return 0; - res = data->payload; switch (hdr->opcode) { case APR_BASIC_RSP_RESULT: { + res = data->payload; if (res->status) { dev_err(afe->dev, "cmd = 0x%x returned error = 0x%x\n", res->opcode, res->status); @@ -1043,8 +1045,10 @@ static int q6afe_callback(struct apr_device *adev, const struct apr_resp_pkt *da } break; case AFE_CMD_RSP_REMOTE_LPASS_CORE_HW_VOTE_REQUEST: + vote_res = data->payload; afe->result.opcode = hdr->opcode; - afe->result.status = res->status; + afe->result.status = 0; + afe->vote_result = *vote_res; wake_up(&afe->wait); break; default: @@ -1955,6 +1959,8 @@ int q6afe_vote_lpass_core_hw(struct device *dev, uint32_t hw_block_id, AFE_CMD_RSP_REMOTE_LPASS_CORE_HW_VOTE_REQUEST); if (ret) dev_err(afe->dev, "AFE failed to vote (%d)\n", hw_block_id); + else + *client_handle = afe->vote_result; return ret; } -- 2.55.0
