2023-05-08 11:03:29

by Richard Fitzgerald

[permalink] [raw]
Subject: [PATCH] soundwire: intel: Make DEV_NUM_IDA_MIN a module param

Add a module param so that globally-unique peripheral ID
allocation is only enabled if wanted.

The globally-unique IDs were introduced by
commit c60561014257
("soundwire: bus: allow device number to be unique at system level")

and
commit 1f2dcf3a154a ("soundwire: intel: set dev_num_ida_min")

Assigning globally-unique IDs limits the total number of
peripherals in a system, and the above two commits limit to a
maximum of 8 peripherals. We now have hardware with more than
8 peripherals in total, so this limit is a problem. As the
original commit says that it is only for debug it can be made
optional.

Signed-off-by: Richard Fitzgerald <[email protected]>
---
drivers/soundwire/intel_auxdevice.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/intel_auxdevice.c b/drivers/soundwire/intel_auxdevice.c
index b21e86084f7b..9ebbf652e47a 100644
--- a/drivers/soundwire/intel_auxdevice.c
+++ b/drivers/soundwire/intel_auxdevice.c
@@ -23,8 +23,13 @@
#include "intel.h"
#include "intel_auxdevice.h"

-/* IDA min selected to avoid conflicts with HDaudio/iDISP SDI values */
-#define INTEL_DEV_NUM_IDA_MIN 4
+/*
+ * sdw_dev_num_min: Set to non-zero to enable globally-unique peripheral IDs.
+ * The value is the minimum ID that will be allocated.
+ */
+static int intel_dev_num_ida_min;
+module_param_named(sdw_dev_num_min, intel_dev_num_ida_min, int, 0444);
+MODULE_PARM_DESC(sdw_dev_num_min, "SoundWire Intel Master min globally-unique ID (0 to disable)");

#define INTEL_MASTER_SUSPEND_DELAY_MS 3000

@@ -148,7 +153,7 @@ static int intel_link_probe(struct auxiliary_device *auxdev,
cdns->msg_count = 0;

bus->link_id = auxdev->id;
- bus->dev_num_ida_min = INTEL_DEV_NUM_IDA_MIN;
+ bus->dev_num_ida_min = intel_dev_num_ida_min;
bus->clk_stop_timeout = 1;

sdw_cdns_probe(cdns);
--
2.30.2


2023-05-08 14:08:29

by Pierre-Louis Bossart

[permalink] [raw]
Subject: Re: [PATCH] soundwire: intel: Make DEV_NUM_IDA_MIN a module param



On 5/8/23 05:39, Richard Fitzgerald wrote:
> Add a module param so that globally-unique peripheral ID
> allocation is only enabled if wanted.
>
> The globally-unique IDs were introduced by
> commit c60561014257
> ("soundwire: bus: allow device number to be unique at system level")
>
> and
> commit 1f2dcf3a154a ("soundwire: intel: set dev_num_ida_min")
>
> Assigning globally-unique IDs limits the total number of
> peripherals in a system, and the above two commits limit to a
> maximum of 8 peripherals. We now have hardware with more than
> 8 peripherals in total, so this limit is a problem. As the
> original commit says that it is only for debug it can be made
> optional.
I think it's a misunderstanding, the introduction of these IDs was
related to hardware programming sequences, not just debug.

I'll talk to Richard on this, please do not apply this patch for now.

> Signed-off-by: Richard Fitzgerald <[email protected]>
> ---
> drivers/soundwire/intel_auxdevice.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/soundwire/intel_auxdevice.c b/drivers/soundwire/intel_auxdevice.c
> index b21e86084f7b..9ebbf652e47a 100644
> --- a/drivers/soundwire/intel_auxdevice.c
> +++ b/drivers/soundwire/intel_auxdevice.c
> @@ -23,8 +23,13 @@
> #include "intel.h"
> #include "intel_auxdevice.h"
>
> -/* IDA min selected to avoid conflicts with HDaudio/iDISP SDI values */
> -#define INTEL_DEV_NUM_IDA_MIN 4
> +/*
> + * sdw_dev_num_min: Set to non-zero to enable globally-unique peripheral IDs.
> + * The value is the minimum ID that will be allocated.
> + */
> +static int intel_dev_num_ida_min;
> +module_param_named(sdw_dev_num_min, intel_dev_num_ida_min, int, 0444);
> +MODULE_PARM_DESC(sdw_dev_num_min, "SoundWire Intel Master min globally-unique ID (0 to disable)");
>
> #define INTEL_MASTER_SUSPEND_DELAY_MS 3000
>
> @@ -148,7 +153,7 @@ static int intel_link_probe(struct auxiliary_device *auxdev,
> cdns->msg_count = 0;
>
> bus->link_id = auxdev->id;
> - bus->dev_num_ida_min = INTEL_DEV_NUM_IDA_MIN;
> + bus->dev_num_ida_min = intel_dev_num_ida_min;
> bus->clk_stop_timeout = 1;
>
> sdw_cdns_probe(cdns);