Re: [PATCH v7 1/2] module: add SCMI device table alias support

[Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>]

On 9/18/26 12:02, Hans de Goede wrote:
> Hi Daniel,
> 
> On 18-Sep-26 11:53, Daniel Lezcano wrote:
>>
>> Hi Hans,
>>
>> thanks for taking care of that
>>
>>
>> On 9/18/26 11:29, Hans de Goede wrote:
>>> From: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
>>>
>>> SCMI client drivers already describe their bus match data with
>>> MODULE_DEVICE_TABLE(scmi, ...), but modpost does not know how to consume
>>> SCMI device tables. As a result, SCMI modules do not get generated module
>>> aliases from their id tables.
>>>
>>> Move struct scmi_device_id to mod_devicetable.h so it has a fixed layout
>>> visible to modpost, add the corresponding generated offsets and teach
>>> file2alias to emit scmi:<protocol>:<name> aliases.
>>>
>>> Use the same stable alias format for SCMI device uevents and sysfs
>>> modaliases. The previous string included the instance-specific device
>>> name, which is not useful for matching modules.
>>>
>>> Assisted-by: Codex:GPT-5.5
>>> Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
>>> Tested-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
>>> Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
>>> Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
>>> ---
>>

[ ... ]

>>>    #include <linux/bitfield.h>
>>> +#include <linux/device-id/scmi.h>
>>>    #include <linux/device.h>
>>>    #include <linux/notifier.h>
>>>    #include <linux/types.h>
>>> @@ -951,11 +952,6 @@ struct scmi_device {
>>>      #define to_scmi_dev(d) container_of_const(d, struct scmi_device, dev)
>>>    -struct scmi_device_id {
>>> -    u8 protocol_id;
>>> -    const char *name;
>>> -};
>>> -
>>
>> What is the reason of converting the char * to a fixed array? That limits the name and may result in truncation and potentially name collision, no ?
> 
> Because of how modpost works to generate modaliases inside the .ko
> any string buffers in device_id structs need to have a fixed length.
> 
> So the truncation / name collision issue pretty much applies to all
> foo_device_id structs in the kernel. People should now to make sure
> that any strings used will fit inside the fixed string. And I would
> expect the compiler to warn for overly long strings.
Ok, thanks for the clarification