Re: [PATCH v2 3/5] ASoC: qcom: q6prm: add support for LPASS LPR resource voting

[Prasad Kumpatla]

On 7/14/2026 1:13 PM, Srinivas Kandagatla wrote:
> On 7/13/26 7:45 PM, Prasad Kumpatla wrote:
> > Add support for issuing LPASS low-power resource (LPR) votes through
> > the PRM interface.
> >
> > Some platforms (e.g. Hawi) require the LPASS to be kept active via LPR
> > resource voting instead of the existing hardware core vote mechanism.
> > Handle this by introducing support for PARAM_ID_RSC_CPU_LPR when the
> > LPR vote clock ID is requested.
> >
> > For LPR requests, use the appropriate parameter ID and payload format
> > to disable CPU subsystem sleep, ensuring that the LPASS register space
> > remains accessible.
> >
> > Also add the corresponding clock mapping for LPASS_HW_LPR_VOTE and make
> > the q6dsp clock ID range consistent with the dt-bindings by deriving
> > it from Q6AFE_MAX_CLK_ID.
> >
> > Signed-off-by: Prasad Kumpatla <prasad.kumpatla@xxxxxxxxxxxxxxxx>
> > ---
> >   sound/soc/qcom/qdsp6/q6dsp-lpass-clocks.c |  2 +-
> >   sound/soc/qcom/qdsp6/q6prm-clocks.c       |  2 ++
> >   sound/soc/qcom/qdsp6/q6prm.c              | 17 +++++++++++++----
> >   sound/soc/qcom/qdsp6/q6prm.h              |  1 +
> >   4 files changed, 17 insertions(+), 5 deletions(-)
> >
> > diff --git a/sound/soc/qcom/qdsp6/q6dsp-lpass-clocks.c b/sound/soc/qcom/qdsp6/q6dsp-lpass-clocks.c
> > index 03838582a..79527a367 100644
> > --- a/sound/soc/qcom/qdsp6/q6dsp-lpass-clocks.c
> > +++ b/sound/soc/qcom/qdsp6/q6dsp-lpass-clocks.c
> > @@ -12,7 +12,7 @@
> >   #include <dt-bindings/sound/qcom,q6dsp-lpass-ports.h>
> >   #include "q6dsp-lpass-clocks.h"
> >   
> > -#define Q6DSP_MAX_CLK_ID			104
> > +#define Q6DSP_MAX_CLK_ID			Q6AFE_MAX_CLK_ID
> >   #define Q6DSP_LPASS_CLK_ROOT_DEFAULT		0
> >   
> >   
> > diff --git a/sound/soc/qcom/qdsp6/q6prm-clocks.c b/sound/soc/qcom/qdsp6/q6prm-clocks.c
> > index 4c574b48a..2b2b3872e 100644
> > --- a/sound/soc/qcom/qdsp6/q6prm-clocks.c
> > +++ b/sound/soc/qcom/qdsp6/q6prm-clocks.c
> > @@ -63,6 +63,8 @@ static const struct q6dsp_clk_init q6prm_clks[] = {
> >   		       "LPASS_HW_MACRO"),
> >   	Q6DSP_VOTE_CLK(LPASS_HW_DCODEC_VOTE, Q6PRM_HW_CORE_ID_DCODEC,
> >   		       "LPASS_HW_DCODEC"),
> > +	Q6DSP_VOTE_CLK(LPASS_HW_LPR_VOTE, Q6PRM_HW_LPR_VOTE,
> > +		       "LPASS_HW_LPR_VOTE"),
> >   };
> >   
> >   static const struct q6dsp_clk_desc q6dsp_clk_q6prm __maybe_unused = {
> > diff --git a/sound/soc/qcom/qdsp6/q6prm.c b/sound/soc/qcom/qdsp6/q6prm.c
> > index 04892fb44..7a7a1d3d5 100644
> > --- a/sound/soc/qcom/qdsp6/q6prm.c
> > +++ b/sound/soc/qcom/qdsp6/q6prm.c
> > @@ -31,10 +31,16 @@ struct q6prm {
> >   #define PARAM_ID_RSC_HW_CORE		0x08001032
> >   #define PARAM_ID_RSC_LPASS_CORE		0x0800102B
> >   #define PARAM_ID_RSC_AUDIO_HW_CLK	0x0800102C
> > +#define PARAM_ID_RSC_CPU_LPR		0x08001A6E
> > +
> > +#define LPR_CPU_SS_SLEEP_DISABLED	0x1
> >   
> >   struct prm_cmd_request_hw_core {
> >   	struct apm_module_param_data param_data;
> > -	uint32_t hw_clk_id;
> > +	union {
> > +		u32 hw_clk_id;
> > +		u32 lpr_state;
> > +	};
> >   } __packed;
> >   
> >   struct prm_cmd_request_rsc {
> > @@ -62,6 +68,7 @@ static int q6prm_set_hw_core_req(struct device *dev, uint32_t hw_block_id, bool
> >   	struct prm_cmd_request_hw_core *req;
> >   	gpr_device_t *gdev = prm->gdev;
> >   	uint32_t opcode, rsp_opcode;
> > +	bool lpr_req = (hw_block_id == Q6PRM_HW_LPR_VOTE);
> >   
> >   	if (enable) {
> >   		opcode = PRM_CMD_REQUEST_HW_RSC;
> > @@ -82,10 +89,13 @@ static int q6prm_set_hw_core_req(struct device *dev, uint32_t hw_block_id, bool
> >   
> >   	param_data->module_instance_id = GPR_PRM_MODULE_IID;
> >   	param_data->error_code = 0;
> > -	param_data->param_id = PARAM_ID_RSC_HW_CORE;
> > +	param_data->param_id = lpr_req ? PARAM_ID_RSC_CPU_LPR : PARAM_ID_RSC_HW_CORE;
> >   	param_data->param_size = sizeof(*req) - APM_MODULE_PARAM_DATA_SIZE;
> >   
> > -	req->hw_clk_id = hw_block_id;
> > +	if (lpr_req)
> > +		req->lpr_state = LPR_CPU_SS_SLEEP_DISABLED;
> this does not make sense, this should be set based on enable flag, here
> you are disabling the LPR for both enable and disable request.
Hi Srini,

The intent here is slightly different from a typical enable/disable 
state variable.
For PARAM_ID_RSC_CPU_LPR, the payload field (lpr_state) identifies the 
low-power
resource being controlled, and the DSP API defines a single valid value: 
LPR_CPU_SS_SLEEP_DISABLED(0x1).

The actual operation is encoded by the PRM command:
PRM_CMD_REQUEST_HW_RSC + LPR_CPU_SS_SLEEP_DISABLED  -  Requests the 
resource and prevents the subsystem from entering the corresponding 
low-power state.
PRM_CMD_RELEASE_HW_RSC + LPR_CPU_SS_SLEEP_DISABLED    - Releases the 
resource, allowing the subsystem to enter that low-power state again.

In other words, the payload does not represent the desired runtime state 
and is therefore not toggled based on the enable flag.
Instead, the request/release opcode determines whether the low-power 
state is being blocked or re-enabled, while lpr_state remains 
LPR_CPU_SS_SLEEP_DISABLED for both operations.

Hope this clarifies why the payload remains unchanged across request and 
release paths.

> > +	else
> > +		req->hw_clk_id = hw_block_id;
> >   
> >   	return q6prm_send_cmd_sync(prm, pkt, rsp_opcode);
> >   }
> > @@ -94,7 +104,6 @@ int q6prm_vote_lpass_core_hw(struct device *dev, uint32_t hw_block_id,
> >   			     const char *client_name, uint32_t *client_handle)
> >   {
> >   	return q6prm_set_hw_core_req(dev, hw_block_id, true);
> > -
> unnecessary change.
Agreed, the whitespace change is unrelated and will be dropped in the 
next revision.

Thanks,
Prasad

> >   }
> >   EXPORT_SYMBOL_GPL(q6prm_vote_lpass_core_hw);
> >   
> > diff --git a/sound/soc/qcom/qdsp6/q6prm.h b/sound/soc/qcom/qdsp6/q6prm.h
> > index a988a3208..bd5ee0c40 100644
> > --- a/sound/soc/qcom/qdsp6/q6prm.h
> > +++ b/sound/soc/qcom/qdsp6/q6prm.h
> > @@ -87,6 +87,7 @@
> >   #define Q6PRM_LPASS_CLK_ROOT_DEFAULT	0
> >   #define Q6PRM_HW_CORE_ID_LPASS		1
> >   #define Q6PRM_HW_CORE_ID_DCODEC		2
> > +#define Q6PRM_HW_LPR_VOTE		3
> >   
> >   int q6prm_set_lpass_clock(struct device *dev, int clk_id, int clk_attr,
> >   			  int clk_root, unsigned int freq);