Hi Shimodaさん > From: Yoshihiro Shimoda > Sent: Tuesday, May 07, 2019 5:17 AM > > For the most part, the RZ/A2 has the same USB 2.0 host and device > > HW as the R-Car Gen3, so we can reuse a lot of the code. > > > > However, there are a couple extra register bits, and the CFIFO > > register 8-bit access works a little different (weird, no idea why). > > This is just my gut feeling, but if we set the BIGEND bit in the CFIFOSEL > of RZ/A2M (R-Car Gen3 doesn't have such a bit though), could the original > code work correctly? I just tried to set CFIFOSEL.BIGEND = 1 * Set CFIFOSEL.BIGEND = 1 * Write 8-bit values to CFIFO (same method as R-Car) * Set CFIFOSEL.BIGEND = 0 The result is bad. But, then I tried this: * Set CFIFOSEL.MBW = 0 (CFIFO port access = 8-bit) * Write 8-bit values to CFIFO * Set CFIFOSEL.MBW = 2 (CFIFO port access = 32-bit) Code: u16 cfifosel = usbhs_read(priv, fifo->sel); usbhs_write(priv, fifo->sel, cfifosel & 0xF3FF); // MBW = 8-bit for (i = 0; i < len; i++) iowrite8(buf[i], addr); //same address each time usbhs_write(priv, fifo->sel, cfifosel); // MBW = 32-bit This method works good. (I assume this method would work with R-Car also) But...then we have extra register reads and writes. Register accesses are slower, so performance is lower. So, I prefer my original method: if (usbhsc_flags_has(priv, USBHSF_CFIFO_BYTE_ADDR)) for (i = 0; i < len; i++) iowrite8(buf[i], addr + (i & 0x03)); else for (i = 0; i < len; i++) iowrite8(buf[i], addr + (0x03 - (i & 0x03))); Do you agree? Chris
