On 5/7/19 12:19 AM, Vinod Koul wrote:
On 06-05-19, 11:46, Pierre-Louis Bossart wrote:
On 5/6/19 11:22 AM, Vinod Koul wrote:
On 06-05-19, 17:19, Greg KH wrote:
On Mon, May 06, 2019 at 09:42:35AM -0500, Pierre-Louis Bossart wrote:
+
+int sdw_sysfs_slave_init(struct sdw_slave *slave)
+{
+ struct sdw_slave_sysfs *sysfs;
+ unsigned int src_dpns, sink_dpns, i, j;
+ int err;
+
+ if (slave->sysfs) {
+ dev_err(&slave->dev, "SDW Slave sysfs is already
initialized\n");
+ err = -EIO;
+ goto err_ret;
+ }
+
+ sysfs = kzalloc(sizeof(*sysfs), GFP_KERNEL);
Same question as patch 1, why a new device?
yes it's the same open. In this case, the slave devices are defined at a
different level so it's also confusing to create a device to represent the
slave properties. The code works but I am not sure the initial directions
are correct.
You can just make a subdir for your attributes by using the attribute
group name, if a subdirectory is needed just to keep things a bit more
organized.
The key here is 'a subdir' which is not the case here. We did discuss
this in the initial patches for SoundWire which had sysfs :)
The way MIPI disco spec organized properties, we have dp0 and dpN
properties each of them requires to have a subdir of their own and that
was the reason why I coded it to be creating a device.
Vinod, the question was not for dp0 and dpN, it's fine to have
subdirectories there, but rather why we need separate devices for the master
and slave properties.
Slave does not have a separate device. IIRC the properties for Slave are
in /sys/bus/soundwire/device/<slave>/...
I am not sure this is correct
ACPI defines the slaves devices under
/sys/bus/acpi/PRP0001, e.g.
/sys/bus/acpi/devices/PRP00001:00/device:17# ls
adr mipi-sdw-dp-5-sink-subproperties
intel-endpoint-descriptor-0 mipi-sdw-dp-6-source-subproperties
intel-endpoint-descriptor-1 mipi-sdw-dp-7-sink-subproperties
mipi-sdw-dp-0-subproperties mipi-sdw-dp-8-source-subproperties
mipi-sdw-dp-1-sink-subproperties path
mipi-sdw-dp-1-source-subproperties physical_node
mipi-sdw-dp-2-sink-subproperties power
mipi-sdw-dp-2-source-subproperties subsystem
mipi-sdw-dp-3-sink-subproperties uevent
mipi-sdw-dp-4-source-subproperties
but the sysfs for slaves is shown as
/sys/bus/acpi/devices/PRP00001:00/int-sdw.0/sdw:0:25d:700:0:0# ls
bank_delay_support master_count sink_ports
ch_prep_timeout mipi_revision source_ports
clk_stop_mode1 modalias src-dp2
clk_stop_timeout p15_behave src-dp4
dp0 paging_support subsystem
driver power test_mode_capable
firmware_node reset_behave uevent
hda_reg simple_clk_stop_capable wake_capable
high_PHY_capable sink-dp1
index_reg sink-dp3
and in sys/bus/soundwire/devices/sdw:0:25d:700:0:0# ls
bank_delay_support master_count sink_ports
ch_prep_timeout mipi_revision source_ports
clk_stop_mode1 modalias src-dp2
clk_stop_timeout p15_behave src-dp4
dp0 paging_support subsystem
driver power test_mode_capable
firmware_node reset_behave uevent
hda_reg simple_clk_stop_capable wake_capable
high_PHY_capable sink-dp1
index_reg sink-dp3
So I would think we *do* create a new device for each slave instead of
using the one that's already exposed by ACPI.
For master yes we can skip the device creation, it was done for
consistency sake of having these properties ties into sys/bus/soundwire/
I don't mind if they are shown up in respective device node (PCI/platform
etc) /sys/bus/foo/device/<>
But for creating subdirectories you would need the new dpX devices.
yes, that's agreed.
