Hi Amit, On 9/21/2021 12:04 AM, Amit Pundir wrote: > Hi Wesley, > > On Tue, 21 Sept 2021 at 02:44, Wesley Cheng <wcheng@xxxxxxxxxxxxxx> wrote: >> >> Hi Amit, >> >> On 9/20/2021 1:45 PM, Amit Pundir wrote: >>> Hi Wesley, All, >>> >>> I see a reboot loop on Xiaomi Pocophone F1 (sdm845) with TX FIFO >>> resize patches which landed in v5.15-rc1. Upstream commit cefdd52fa045 >>> "usb: dwc3: dwc3-qcom: Enable tx-fifo-resize property by default" to >>> be specific, which switched on this feature by default. >>> >>> At times the phone crashes into the fastboot mode after the reboot >>> loop, but mostly end up booting to UI after a while. This is what it >>> looks like https://people.linaro.org/~amit.pundir/beryllium-userdebug/PXL_20210920_162749483.mp4. >>> >> >> I believe Android will attempt a number of bootup sequences and if it >> fails, it falls back to fastboot mode. Are there any available logs you >> might be able to collect to see where the issue is? > > It is a stock phone with no UART access, so I can't get early crash > logs unless I'm booted up to adb shell. I can try getting some info > using pstore-ramoops but warm reset support for sdm845 was not > upstreamed when I tried using that the last time. > I see, can we maybe avoid the actual resizing by commenting out the following writel() calls, but let the fifo resize logic calculate the EPs? void dwc3_gadget_clear_tx_fifos(struct dwc3 *dwc) { ... /* Don't change TXFRAMNUM on usb31 version */ size = DWC3_IP_IS(DWC3) ? 0 : dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(num >> 1)) & DWC31_GTXFIFOSIZ_TXFRAMNUM; /* Comment the dwc3_writel() */ //dwc3_writel(dwc->regs, DWC3_GTXFIFOSIZ(num >> 1), size); and static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep) { ... /* Comment the dwc3_writel() */ //dwc3_writel(dwc->regs, DWC3_GTXFIFOSIZ(dep->number >> 1), fifo_size); dwc->num_ep_resized++; Those 2 writel() would be the one that actually programs the TXFIFO register. I hope when commented out, no resize should actually happen anymore. With this, hopefully we can get some logs from the device at least :) >> >>> PocoF1 does support TX fifo resizing as I can see that in the >>> downstream dts. So maybe it is the tx-fifo-max-num which need to be >>> adjusted for the device? I couldn't find the tx-fifo-max-num >>> equivalent in the downstream tree though >>> https://github.com/MiCode/Xiaomi_Kernel_OpenSource/tree/dipper-q-oss/ >>> >> >> I assume that you've already confirmed reverting that change resolves >> the constant reboots? > > Yes reverting that change resolves the reboot loop issue. Speaking of > which, since no other platform seem to be running into this issue and > "tx-fifo-max-num" property is apparently not at fault either, is it > reasonable to skip adding "tx-fifo-resize" property for PocoF1 using > of_machine_is_compatible("xiaomi,beryllium") as a workaround? > Since SDM845 does technically support txfifo resize downstream, let me see if I can figure out what is different on this particular device after getting the logs. Thanks Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
