On Thu, Jul 21, 2016 at 10:36:42AM +0300, Emmanuel Grumbach wrote: > On Thu, Jul 21, 2016 at 10:09 AM, Stanislaw Gruszka <sgruszka@xxxxxxxxxx> wrote: > > On Tue, Jul 19, 2016 at 03:00:37PM +0200, Michal Kazior wrote: > >> Firmware files are versioned to prevent older > >> driver instances to load unsupported firmware > >> blobs. This is reflected with a fallback logic > >> which attempts to load several firmware files. > >> > >> This however produced a lot of unnecessary > >> warnings sometimes confusing users and leading > >> them to rename firmware files making things even > >> more confusing. > > > > This happens on kernels configured with > > CONFIG_FW_LOADER_USER_HELPER_FALLBACK and cause not only ugly warnings, > > but also 60 seconds delay before loading next firmware version. > > For some reason RHEL kernel needs above config option, so this > > patch is very welcome from my perspective. > > > > Sorry for my ignorance but how does the firmware loading work if not > with udev's help? I'm not sure exactly, but I think kernel VFS layer is capable to copy file data directly from mounted filesystem without user space helper. > As you can imagine, iwlwifi is suffering from the > same problem and I would be interested in applying the same change, > but I'd love to understand a bit more :) Yes, iwlwifi (and some other drivers) suffer from this. However this happen when the newest firmware version is not installed on the system and CONFIG_FW_LOADER_USER_HELPER_FALLBACK is enabled. What I suppose it's not common. I started to see this currently, because that option was enabled on RHEL kernel. BTW: I think Prarit iwlwifi thermal_zone problem was happened because of that, i.e. thermal device was not functional because f/w wasn't loaded due to big delay. I'm not sure if replacing to request_firmware_direct() is a good fix though. For example I can see this problem also on brcmfmac, which use request_firmware_nowait(). I think I would rather prefer special helper for firmware drivers that needs user helper and have request_firmware() be direct as default. Stanislaw -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
