On 12/3/21 11:14, Hans de Goede wrote:
Hi,
On 12/3/21 12:06, Andy Shevchenko wrote:
On Thu, Dec 02, 2021 at 04:24:19PM +0000, Stefan Binding wrote:
From: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
Revert commit bdc7ca008e1f ("spi: Remove unused function
spi_busnum_to_master()")
This function is needed for the spi version of i2c multi
instantiate driver.
I understand the intention, but I have no clue from this series (it lacks of
proper cover letter, it lacks of much better and justified commit message in
the patch 3) what is the actual issue. Without these to be provided it's no go
for the series. Please, provide much better description what is the actual
issue you are trying to solve (from patch 3 my guts telling me that this can
be achieved differently without this code being involved).
Yes I assume that eventually there will be a follow-up which will
actually add some new ACPI HIDs to the new bus-multi-instantiate.c file ?
Yes, we are developing an HDA sound driver for the HID CSC3551,
which is used for laptops that use SPI or I2C.
And in that series is where we plan to put a patch to add that HID.
Can we please have (some of) those patches as part of the next
version, so that we can see how you will actually use this?
The series is this one https://lkml.org/lkml/2021/11/23/723, but
the SPI HID was not ready to be sent in that version, but will be
part of the next submission.
Also I'm wondering is this actually about ACPI device's having multiple
SpiSerialBusV2 resources in a single _CRS resource list ?
yes, a single _CRS with 2 or 4 SpiSerialBusV2 inside.
Or do you plan to use this for devices with only a single
I2cSerialBusV2 or SpiSerialBusV2 resource to e.g. share IRQ lookup
code between the 2 cases ?
No, the minimum number SpiSerialBusV2 or I2cSerialBusV2 inside the
_CRS is two.
If you plan to use this for devices with only a single
I2cSerialBusV2 or SpiSerialBusV2 resource, then I'm going to have to
nack this.
Each ACPI HID which needs to be handled in this code also needs an
entry in the i2c_multi_instantiate_ids[] list in drivers/acpi/scan.c
which is code which ends up loaded on every single ACPI system, so
we really only want to add HIDs there for the special case of having
multiple I2cSerialBusV2 or SpiSerialBusV2 resources in a single
ACPI Device / ACPI fwnode.
If you are looking to use this as a way to share code for other reasons
(which is a good goal to strive for!) please find another way, such
as e.g. adding some helper functions to drivers/gpio/gpiolib-acpi.c
(note there already are a couple of helpers there which you may use).
No, we only want to multi instantiate SPI or I2C devices from a single _CRS.
Regards,
Hans
We sent a request to the laptop vendor about releasing the SPI DSDT, and
after that gets cleared, we will send it to you for review. That will
likely be next.
Thanks
Lucas Tanure
