Hi Doug, On 06/03/18 18:00, Doug Anderson wrote: > Hi, > > On Tue, Mar 6, 2018 at 3:58 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> Hi all, >> >> On 01/03/18 08:43, Heiko Stübner wrote: >>> Am Dienstag, 27. Februar 2018, 21:47:11 CET schrieb Douglas Anderson: >>>> Back in the early days when gru devices were still under development >>>> we found an issue where the WiFi reset line needed to be configured as >>>> early as possible during the boot process to avoid the WiFi module >>>> being in a bad state. >>>> >>>> We found that the way to get the kernel to do this in the earliest >>>> possible place was to configure this line in the pinctrl hogs, so >>>> that's what we did. For some history here you can see >>>> <http://crosreview.com/368770>. After the time that change landed in >>>> the kernel, we landed a firmware change to configure this line even >>>> earlier. See <http://crosreview.com/399919>. However, even after the >>>> firmware change landed we kept the kernel change to deal with the fact >>>> that some people working on devices might take a little while to >>>> update their firmware. >>>> >>>> At this there are definitely zero devices out in the wild that have >>>> firmware without the fix in it. Specifically looking in the firmware >>>> branch several critically important fixes for memory stability landed >>>> after the patch in coreboot and I know we didn't ship without those. >>>> Thus, by now, everyone should have the new firmware and it's safe to >>>> not have the kernel set this up in a pinctrl hog. >>>> >>>> Historically, even though it wasn't needed to have this in a pinctrl >>>> hog, we still kept it since it didn't hurt. Pinctrl would apply the >>>> default hog at bootup and then would never touch things again. That >>>> all changed with commit 981ed1bfbc6c ("pinctrl: Really force states >>>> during suspend/resume"). After that commit then we'll re-apply the >>>> default hog at resume time and that can screw up the reset state of >>>> WiFi. ...and on rk3399 if you touch a device on PCIe in the wrong way >>>> then the whole system can go haywire. That's what was happening. >>>> Specifically you'd resume a rk3399-gru-* device and it would mostly >>>> resume, then would crash with some crazy weird crash. >>>> >>>> One could say, perhaps, that the recent pinctrl change was at fault >>>> (and should be fixed) since it changed behavior. ...but that's not >>>> really true. The device tree for rk3399-gru is really to blame. >>>> Specifically since the pinctrl is defined in the hog and not in the >>>> "wlan-pd-n" node then the actual user of this pin doesn't have a >>>> pinctrl entry for it. That's bad. >>>> >>>> Let's fix our problems by just moving the control of >>>> "wlan_module_reset_l pinctrl" out of the hog and put them in the >>>> proper place. >>>> >>>> NOTE: in theory, I think it should actually be possible to have a pin >>>> controlled _both_ by the hog and by an actual device. Once the device >>>> claims the pin I think the hog is supposed to let go. I'm not 100% >>>> sure that this works and in any case this solution would be more >>>> complex than is necessary. >>>> >>>> Reported-by: Marc Zyngier <marc.zyngier@xxxxxxx> >>>> Fixes: 48f4d9796d99 ("arm64: dts: rockchip: add Gru/Kevin DTS") >>>> Fixes: 981ed1bfbc6c ("pinctrl: Really force states during suspend/resume") >>>> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> >>> >>> applied as fix for 4.16 with the 2 Tested-tags >> Sorry to rain on everyone's parade, but further testing shows that this >> patch may not be enough to restore a reliable s2r. My initial testing >> did show that we were resuming without the VOP errors, but there seem to >> be further issues (I'm loosing the keyboard and the trackpad after >> resume on Kevin). >> >> Applying my initial hack makes it work again. I suspect that there are >> more hog pins that need tweaking, but I'm a bit out of my depth here. > > Are you positive you weren't just wearing your lucky hat when you > tested your patch and then took it off when you tested mine? As far So far, I seem to have a 100% success rate in resuming with my silly hack, whist your DT patch alone only gives me a 50% rate at best. > as I can see the only hogs left on kevin are: > > &ap_pwroff /* AP will auto-assert this when in S3 */ > &clk_32k /* This pin is always 32k on gru boards */ > > Those map to: > > ap_pwroff: ap-pwroff { > rockchip,pins = <1 5 RK_FUNC_1 &pcfg_pull_none>; > }; > > clk_32k: clk-32k { > rockchip,pins = <0 0 RK_FUNC_2 &pcfg_pull_none>; > }; > > So I added some printouts at suspend/resume time. Specifically I set > a boolean to "true" for the duration rockchip_pinctrl_suspend() and > rockchip_pinctrl_resume() and this turned on a printout in > rockchip_set_mux(). My printout looked like this (yeah, I know it's a > whitespace-damaged patch just to show what I'm doing): > > + regmap_read(regmap, reg, &before); > data = (mask << (bit + 16)); > rmask = data | (data >> 16); > data |= (mux & mask) << bit; > ret = regmap_update_bits(regmap, reg, rmask, data); > > + regmap_read(regmap, reg, &after); > + > + if (DOUG) { > + dev_info(info->dev, > + "setting mux of GPIO%d-%d to %d; %#010x=>%#010x\n", > + bank->bank_num, pin, mux, reg, before, after); > + } > > ...and a similar one in rockchip_set_pull(). That showed this at resume time: > > [ 62.284427] rockchip-pinctrl pinctrl: setting mux of GPIO1-5 to 1; > 0x00009400=>0x00009400 > [ 62.294423] rockchip-pinctrl pinctrl: setting pull of GPIO1-5; > 0x000041aa=>0x000041aa > [ 62.303343] rockchip-pinctrl pinctrl: setting mux of GPIO0-0 to 2; > 0x00005002=>0x00005002 > [ 62.313240] rockchip-pinctrl pinctrl: setting pull of GPIO0-0; > 0x00000ddc=>0x00000ddc > [ > > Said another way: pinmux and pull isn't actually changing due to the > hogs. We can see if something else could be changing, but I'd really > want to be sure you're certain that the hogs are causing you > problems... I cannot say for sure that the hogs are the issue. But I thought that they were the only pins affected by 981ed1bfbc6c... If this patch can affect other pins, then I'm probably barking up the wrong tree. Thanks, M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
