On 2/1/21 10:18 PM, Vinod Koul wrote:
On 01-02-21, 10:10, Pierre-Louis Bossart wrote:
On 2/1/21 4:14 AM, Vinod Koul wrote:
On 21-01-21, 17:23, Srinivas Kandagatla wrote:
On 21/01/2021 15:12, Pierre-Louis Bossart wrote:
On 1/21/21 6:03 AM, Srinivas Kandagatla wrote:
I totally agree!
If I understand it correctly in Intel case there will be only one Link ID
per bus.
Yes IIUC there would be one link id per bus.
the ida approach gives us unique id for each master,bus I would like to
propose using that everywhere
We have cases where link2 is not used but link0, 1 and 3 are.
Using the IDA would result in master-0,1,2 being shown, that would throw the
integrator off. the link_id is related to hardware and can tolerate gaps,
the IDA is typically always increasing and is across the system, not
controller specific.
We can debate forever but both pieces of information are useful, so my
recommendation is to use both:
snprintf(name, sizeof(name), "master-%d-%d", bus_id, bus->link_id);
I agree we should use both, but does it really make sense for naming? We
can keep name in ida and expose the link_id as a parameter for
integrators to see in sysfs.
That would mean changing the meaning of sysfs properties:
/*
* The sysfs for properties reflects the MIPI description as given
* in the MIPI DisCo spec
*
* Base file is:
* sdw-master-N
* |---- revision
* |---- clk_stop_modes
* |---- max_clk_freq
* |---- clk_freq
* |---- clk_gears
* |---- default_row
* |---- default_col
* |---- dynamic_shape
* |---- err_threshold
*/
N is the link ID in the spec. I am not convinced we'd do the community a
service by unilaterally changing what an external spec means, or add a
property that's kernel-defined while the rest is supposed to come from
firmware. If you want to change the spec then you can contribute
feedback in MIPI circles (MIPI have a mechanism for maintainers to
provide such feedback without company/employer membership requirements)
So either we add a sysfs layer that represents a controller (better in
my opinion so that we can show the link/master count), or keep the
existing hierarchy but expand the name with a unique ID so that Qualcomm
don't get errors with duplicate sysfs link0 entries.
