On Mon, May 18, 2020 at 10:15:45AM -0700, Ben Greear wrote: > > > On 05/18/2020 10:09 AM, Luis Chamberlain wrote: > > On Mon, May 18, 2020 at 09:58:53AM -0700, Ben Greear wrote: > > > > > > > > > On 05/18/2020 09:51 AM, Luis Chamberlain wrote: > > > > On Sat, May 16, 2020 at 03:24:01PM +0200, Johannes Berg wrote: > > > > > On Fri, 2020-05-15 at 21:28 +0000, Luis Chamberlain wrote:> module_firmware_crashed > > > > > > > > > > You didn't CC me or the wireless list on the rest of the patches, so I'm > > > > > replying to a random one, but ... > > > > > > > > > > What is the point here? > > > > > > > > > > This should in no way affect the integrity of the system/kernel, for > > > > > most devices anyway. > > > > > > > > Keyword you used here is "most device". And in the worst case, *who* > > > > knows what other odd things may happen afterwards. > > > > > > > > > So what if ath10k's firmware crashes? If there's a driver bug it will > > > > > not handle it right (and probably crash, WARN_ON, or something else), > > > > > but if the driver is working right then that will not affect the kernel > > > > > at all. > > > > > > > > Sometimes the device can go into a state which requires driver removal > > > > and addition to get things back up. > > > > > > It would be lovely to be able to detect this case in the driver/system > > > somehow! I haven't seen any such cases recently, > > > > I assure you that I have run into it. Once it does again I'll report > > the crash, but the problem with some of this is that unless you scrape > > the log you won't know. Eventually, a uevent would indeed tell inform > > me. > > > > > but in case there is > > > some common case you see, maybe we can think of a way to detect it? > > > > ath10k is just one case, this patch series addresses a simple way to > > annotate this tree-wide. > > > > > > > So maybe I can understand that maybe you want an easy way to discover - > > > > > per device - that the firmware crashed, but that still doesn't warrant a > > > > > complete kernel taint. > > > > > > > > That is one reason, another is that a taint helps support cases *fast* > > > > easily detect if the issue was a firmware crash, instead of scraping > > > > logs for driver specific ways to say the firmware has crashed. > > > > > > You can listen for udev events (I think that is the right term), > > > and find crashes that way. You get the actual crash info as well. > > > > My follow up to this was to add uevent to add_taint() as well, this way > > these could generically be processed by userspace. > > I'm not opposed to the taint, though I have not thought much on it. > > But, if you can already get the crash info from uevent, and it automatically > comes without polling or scraping logs, then what benefit beyond that does > the taint give you? >From a support perspective it is a *crystal* clear sign that the device and / or device driver may be in a very bad state, in a generic way. Luis
