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LS1046a slow write on USB3

Question asked by Marc LEFORESTIER on Jan 15, 2018
Latest reply on Jan 16, 2018 by Pavel Chubakov


I already asked something like that a long time ago, but I prefer ask a fresh question than digging an old one.

I have a linux based on Yocto with a 4.13.5 kernel on a LS1046a rdb card. An USB3 key with a F2FS or Ext4 FS is slow as hell on this card. Writing on it is maxed at 20MB/s, but reading speed is around 220MB/s. I use a script with dd to test the writing speed (see the attached files).

I tried different registers to improve the results :

- SCFG_SNPCNFGCR at 0x15701A4 with or without snooping activated. With snooping, the result is the same on writing but the reading is falling around 100MB/s. So no snooping.

- GSBUSCFG0 at 0x2F0C100, I put the recommended value of 0x2222000F, no enhancement.

- GSBUSCFG1 at 0x2F0C104, I put the recommended value of 0x00000F00, no enhancement.

I don't know what to do. I need a gigabit writing speed for my USB3 stick and I can't go faster than an USB2 stick with this card. I know that my USB stick can do this speed (Kingston Technology DT Ultimate GT), on a PC I can go up to 145MB/s.

Is there somebody with a ls1046a rdb and a working USB3 gigabit speed? What can I configure to speed the USB3 port with a Linux system?

Thank you for your help.