On 7/5/23 14:03, Jakub Kicinski wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On Fri, 30 Jun 2023 01:22:31 +0000 Ajay.Kathat@xxxxxxxxxxxxx wrote: >> To inline the linux-firmware path with driver, the firmware path is changed >> from 'atmel' to 'microchip/wilc'. This path change will be submitted to >> 'linux-firmware' as well. > > How are you going to make this backward compatible? > Users aren't required to update linux-firmware and kernel at the same > time. Thanks for pointing it out. I think, the changes are not fully compatible for upgrading the kernel and 'linux-firmware' individually. After the driver changes, the 'linux-firmware' upgrade is necessary. The kernel and 'linux-firmware' can be upgraded independently, so two combinations are possible for the upgrade. updated driver : uses modified path(microchip/wilc) to load FW. updated 'linux-firmware': FW file is at modified path(microchip/wilc) 1. updated driver + old 'linux-firmware' : incompatible - The updated driver will look for FW file in '/microchip/wilc' path which is not present in older 'linux-firmware'. Though the interface format is compatible, the driver will fail to load it because the file is not present. 2. old driver + updated 'linux-firmware': compatible - A link is created from new path to old FW path so the old driver should be able to load from linked path. In order to address scenario#1, a fallback method that loads the FW from the older path(/atmel) can be added in the driver. I think that change will make it compatible for scenario#1. Please suggest, if there is a generic/recommended approach to handle backward compatibility for FW path change. Regards, Ajay
