50 MHz SDIO bus not working for some SD cards

[pdp7]

@tommythorn reports:

reading from NFS vs SDcard:

NFS: 22.8 MB/s (the same on my dev box gets 170 MB/s via 10 GbE)
SDCard: 4.6 MB/s (and it's a highend card which will get > 50 MB/s normally).
So, for now and with production hardware, NFS > SDcard. I haven’t tried USB.

FWIW I tested both using dd bs=8192 status=progress,
e.g. sudo dd status=progress bs=8192 if=/dev/mmcblk1 of=/dev/null

@tekkamanninja @MichaelZhuxx: The Seeed FAQ shows 22 MB/s with SD card. I presume this means it was Linux 4.19 that Seeed tested with? Maybe there is a problem with 5.10 on the Fedora image that is causing it to be 4.6 MB/s?

[robertlipe]

Is it possible this is a manifestation of #20 ?

[tommythorn]

I see no traffic in dmesg so I don’t think so

[tgeek77]

I'm getting the same performance. I tested the microsd card on another machine and for 25-30 MB/s but on the BeagleV, I am getting the same performance as @tommythorn.

[MichaelZhuxx]

after update the frequency in dts as below:

--- a/arch/riscv/dts/starfive_vic7100_beagle_v.dts
+++ b/arch/riscv/dts/starfive_vic7100_beagle_v.dts
@@ -556,7 +556,7 @@
                        clocks = <&dwmmc_biuclk>;
                        clock-names = "biu";
                        clock-frequency = <100000000>;
-                       max-frequency = <10000000>;
+                       max-frequency = <50000000>;
                        fifo-depth = <32>;
                        card-detect-delay = <300>;
                        fifo-watermark-aligned;

the system will pop up the below message

[  911.725040] audit: type=1130 audit(1607040900.747:798): pid=1 uid=0 auid=4294967295 ses=429496729'
[  911.816845] audit: type=1131 audit(1607040900.747:799): pid=1 uid=0 auid=4294967295 ses=429496729'
[  920.872770] audit: type=1131 audit(1607040909.887:800): pid=1 uid=0 auid=4294967295 ses=429496729'
[  921.126239] audit: type=1130 audit(1607040910.147:801): pid=1 uid=0 auid=4294967295 ses=429496729'
[  921.177968] audit: type=1131 audit(1607040910.147:802): pid=1 uid=0 auid=4294967295 ses=429496729'
[  921.230732] audit: type=1130 audit(1607040910.237:803): pid=1 uid=0 auid=4294967295 ses=429496729'
[  921.281850] audit: type=1701 audit(1607040910.297:804): auid=4294967295 uid=0 gid=0 ses=4294967291
[  921.404099] audit: type=1334 audit(1607040910.417:805): prog-id=149 op=LOAD
[  921.444058] audit: type=1334 audit(1607040910.417:806): prog-id=150 op=LOAD
[  921.484401] audit: type=1334 audit(1607040910.417:807): prog-id=151 op=LOAD
[  921.524043] audit: type=1325 audit(1607040910.437:808): table=filter family=7 entries=0 op=xt_reg"
[  921.568324] audit: type=1325 audit(1607040910.437:808): table=broute family=7 entries=0 op=xt_reg"
[  946.284639] kauditd_printk_skb: 9 callbacks suppressed

[pdp7]

@tekkamanninja @esmil @geertu interesting results from @MichaelZhuxx when changing the SD card frequency

[MichaelZhuxx]

sorry for missing test data

[root@fedora-starfive ~]# time dd if=/dev/mmcblk1p2 of=/dev/null bs=512k count=5000
5000+0 records in
5000+0 records out
2621440000 bytes (2.6 GB, 2.4 GiB) copied, 110.666 s, 23.7 MB/s

real    1m50.673s
user    0m0.033s
sys     0m15.706s

[esmil]

That's great. I see similar numbers after raising the max frequency to 50MHz.