On 04/04/2023 23:06, Martin Blumenstingl wrote: > Hi Marc, Hello Martin :) > On Tue, Apr 4, 2023 at 6:09 PM Marc Gonzalez wrote: > >> bus-width = <4>; >> cap-sd-highspeed; >> cap-mmc-highspeed; >> max-frequency = <100000000>; > > I would start by comparing the bus mode. You can get it from > /sys/kernel/debug/mmc2/ios > On the vendor kernel it should be in /sys/kernel/debug/sdio/ios (or > similar, I'm typing this from the top of my head). > It will give you insights on the clock and timing that has been > negotiated between the host and card. > > From this information you can get the maximum bus speed, e.g. from [0] > Please note that any card will add overhead for communication, so bus > speed will not be equal to wifi throughput. For the vendor kernel: /sys/kernel/debug/sdio/sdio:0001/state:0x00000001 /sys/kernel/debug/sdio/clock:200000000 /sys/kernel/debug/sdio/ios:clock: 200000000 Hz /sys/kernel/debug/sdio/ios:actual clock: 199999997 Hz /sys/kernel/debug/sdio/ios:vdd: 21 (3.3 ~ 3.4 V) /sys/kernel/debug/sdio/ios:bus mode: 2 (push-pull) /sys/kernel/debug/sdio/ios:chip select: 0 (don't care) /sys/kernel/debug/sdio/ios:power mode: 1 (up) /sys/kernel/debug/sdio/ios:bus width: 2 (4 bits) /sys/kernel/debug/sdio/ios:timing spec: 6 (sd uhs SDR104) /sys/kernel/debug/sdio/ios:signal voltage: 1 (1.80 V) /sys/kernel/debug/sdio/ios:driver type: 0 (driver type B) For mainline: /sys/kernel/debug/mmc2/mmc2:0001/state:0x00000001 /sys/kernel/debug/mmc2/err_stats:# Command Timeout Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Command CRC Errors Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Data Timeout Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Data CRC Errors Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Auto-Cmd Error Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# ADMA Error Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Tuning Error Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ RED Errors: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ GCE Errors: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ ICCE Errors: 0 /sys/kernel/debug/mmc2/err_stats:# Request Timedout: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ Request Timedout: 0 /sys/kernel/debug/mmc2/err_stats:# ICE Config Errors: 0 /sys/kernel/debug/mmc2/err_stats:# Controller Timedout errors: 0 /sys/kernel/debug/mmc2/err_stats:# Unexpected IRQ errors: 0 /sys/kernel/debug/mmc2/err_state:0 /sys/kernel/debug/mmc2/clock:100000000 /sys/kernel/debug/mmc2/caps2:0x00040000 /sys/kernel/debug/mmc2/caps:0x40040105 /sys/kernel/debug/mmc2/ios:clock: 100000000 Hz /sys/kernel/debug/mmc2/ios:actual clock: 99999999 Hz /sys/kernel/debug/mmc2/ios:vdd: 21 (3.3 ~ 3.4 V) /sys/kernel/debug/mmc2/ios:bus mode: 2 (push-pull) /sys/kernel/debug/mmc2/ios:chip select: 0 (don't care) /sys/kernel/debug/mmc2/ios:power mode: 2 (on) /sys/kernel/debug/mmc2/ios:bus width: 2 (4 bits) /sys/kernel/debug/mmc2/ios:timing spec: 5 (sd uhs SDR50) /sys/kernel/debug/mmc2/ios:signal voltage: 1 (1.80 V) /sys/kernel/debug/mmc2/ios:driver type: 0 (driver type B) The clock is indeed running twice as fast on the vendor system. And in SDR104 vs SDR50 mode. Adjusting mainline device tree... /sys/kernel/debug/mmc2/mmc2:0001/state:0x00000001 /sys/kernel/debug/mmc2/err_stats:# Command Timeout Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Command CRC Errors Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Data Timeout Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Data CRC Errors Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Auto-Cmd Error Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# ADMA Error Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# Tuning Error Occurred: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ RED Errors: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ GCE Errors: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ ICCE Errors: 0 /sys/kernel/debug/mmc2/err_stats:# Request Timedout: 0 /sys/kernel/debug/mmc2/err_stats:# CMDQ Request Timedout: 0 /sys/kernel/debug/mmc2/err_stats:# ICE Config Errors: 0 /sys/kernel/debug/mmc2/err_stats:# Controller Timedout errors: 0 /sys/kernel/debug/mmc2/err_stats:# Unexpected IRQ errors: 0 /sys/kernel/debug/mmc2/err_state:0 /sys/kernel/debug/mmc2/clock:200000000 /sys/kernel/debug/mmc2/caps2:0x00040000 /sys/kernel/debug/mmc2/caps:0x40080105 /sys/kernel/debug/mmc2/ios:clock: 200000000 Hz /sys/kernel/debug/mmc2/ios:actual clock: 199999997 Hz /sys/kernel/debug/mmc2/ios:vdd: 21 (3.3 ~ 3.4 V) /sys/kernel/debug/mmc2/ios:bus mode: 2 (push-pull) /sys/kernel/debug/mmc2/ios:chip select: 0 (don't care) /sys/kernel/debug/mmc2/ios:power mode: 2 (on) /sys/kernel/debug/mmc2/ios:bus width: 2 (4 bits) /sys/kernel/debug/mmc2/ios:timing spec: 6 (sd uhs SDR104) /sys/kernel/debug/mmc2/ios:signal voltage: 1 (1.80 V) /sys/kernel/debug/mmc2/ios:driver type: 0 (driver type B) # curl -o /dev/null http://192.168.1.254:8095/fixed/1G % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 1024M 100 1024M 0 0 9747k 0 0:01:47 0:01:47 --:--:-- 9544k With this new setting, WiFi throughput increases 20% (from 60 Mbps to 75 Mbps). (Uggg, I've been using 10^9 for the amount transferred, but it looks to be 2^30 actually. Absolute speeds are actually 7% higher, but doesn't change the conclusion) I also noticed that I reported 11 MB/s (88 Mbps) at the beginning of this thread. This would point to a performance regression caused by my defconfig & device tree changes :( >> vendor DTS has the following child node: >> >> sdio { >> pinname = "sdio"; >> ocr_avail = <0x200080>; /**VDD voltage 3.3 ~ 3.4 */ >> /* max_req_size = <0x20000>; */ /**128KB*/ >> max_req_size = <0x400>; >> card_type = <3>; >> /* 3:sdio device(ie:sdio-wifi), >> * 4:SD combo (IO+mem) card >> */ >> dmode = "pio"; >> }; >> >> Maybe the vendor kernel uses the above information to "boost" >> the performance of the SDIO-based WiFi adapter? > > PIO is also what we support upstream with the > amlogic,dram-access-quirk; (which is enabled for &sd_emmc_a). > This suggests that the pinctrl trick that Neil mentioned is not used here. > > I assume that the wifi driver on the vendor kernel is the brcmdhd (out > of tree) driver, while mainline uses brcmfmac. Correct. hardware/wifi/broadcom/drivers/ap6xxx/bcmdhd.100.10.545.x vs drivers/net/wireless/broadcom/brcm80211/brcmfmac > One idea that comes to my mind is to enable the > amlogic,dram-access-quirk; (and use pio mode on the vendor kernel) for > eMMC or SD card and then compare read/write speeds. If they are > similar-ish then the wifi performance difference is likely caused by > the wifi driver (or in the opposite case: if read/write speeds on > mainline with amlogic,dram-access-quirk; perform worse than the vendor > kernel with pio mode then it's likely that it's a meson-gx-mmc driver > limitation). Thanks for the suggestion. Are you aware whether someone has tried running the bcmdhd driver on mainline? Thanks for the test suggestion. > From my work on the rtw88 SDIO wifi driver I can say that the > meson-gx-mmc driver can push (TX direction) at least 120Mbit/s. > I understand that this is half of what you get with the vendor kernel > - and that this is the wrong direction (you're testing RX while I'm > testing TX). > The point that I want to get across is: I think nobody has the one > answer why wifi performance is lower (personally I'm happy with having > it work at all, performance is second). > So it'll be a process to find the reason, and I think it requires > being creative due to the large amounts of different code (MMC driver, > wifi driver, additional patches...) between mainline and the vendor > kernel. I really appreciate you sharing this insight. Regards.
