On Thu, 2020-10-29 at 11:25 -0700, Brian Norris wrote: > On Wed, Oct 28, 2020 at 7:04 PM Tsuchiya Yuto <kita...@gmail.com> wrote: > > > > On Microsoft Surface devices (PCIe-88W8897), the ps_mode causes > > connection unstable, especially with 5GHz APs. Then, it eventually causes > > fw crash. > > > > This commit disables ps_mode by default instead of enabling it. > > > > Required code is extracted from mwifiex_drv_set_power(). > > > > Signed-off-by: Tsuchiya Yuto <kita...@gmail.com> > > You should read up on WIPHY_FLAG_PS_ON_BY_DEFAULT and > CONFIG_CFG80211_DEFAULT_PS, and set/respect those appropriately (hint: > mwifiex sets WIPHY_FLAG_PS_ON_BY_DEFAULT, and your patch makes this a > lie). Also, this seems like a quirk that you haven't properly worked > out -- if you're working on a quirk framework in your other series, > you should just key into that.
Thanks for the review! I didn't know about the flag, much appreciated. By setting the flag to false explicitly, indeed userspace doesn't try to enable power_save now at least for this short amount of time. I wonder if I can drop the second patch (adding module parameter) now. But I still want to make sure that power_save won't be enabled by userspace tools by default. Regarding quirks, I also don't want to break existing users. So, of course I can try to use the quirk framework if we really can't fix the firmware. > For the record, Chrome OS supports plenty of mwifiex systems with 8897 > (SDIO only) and 8997 (PCIe), with PS enabled, and you're hurting > those. Your problem sounds to be exclusively a problem with the PCIe > 8897 firmware. Actually, I already know that some Chromebooks use these mwifiex cards (but not out PCIe-88W8897) because I personally like chromiumos. I'm always wondering what is the difference. If the difference is firmware, our PCIe-88W8897 firmware should really be fixed instead of this stupid series. Yes, I'm sorry that I know this series is just a stupid one but I have to send this anyway because this stability issue has not been fixed for a long time. I should have added this buglink to every commit as well: BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109681 If the firmware can't be fixed, I'm afraid I have to go this way. It makes no sense to keep enabling power_save for the affected devices if we know it's broken. > As-is, NAK. > > Brian
