On 8/13/2015 8:29 PM, Yunzhi Li wrote: > > > 在 2015/8/14 8:09, John Youn 写道: >> On 8/11/2015 12:57 AM, Yunzhi Li wrote: >>> We initiate dwc2 usb controller in BIOS, when kernel driver >>> start-up we should reset AHB hclk domain to reset all AHB >>> interface registers to default. Without this the FIFO value >>> setting might be incorrect because calculating FIFO size need the >>> power-on value of GRXFSIZ/GNPTXFSIZ/HPTXFSIZ registers. >>> >>> This patch could avoid warnning massage like in rk3288 platform: >>> [ 2.074764] dwc2 ff580000.usb: 256 invalid for >>> host_perio_tx_fifo_size. Check HW configuration. >>> >>> ...... >> I didn't receive the other two patches in this series so I was >> confused about where the "ahb_reset" was coming from when I >> replied to your other patch. >> >> I see you changed the name and documented the DT so never mind. >> >> Another thing is that there probably shouldn't be a debug >> message on the IS_ERR condition since that is the common case >> and of no interest to other platforms. >> >> The other two resets you added aren't used by the driver >> anywhere right? Maybe those should be left out until they are. >> >> John >> > Hi John , > > Here is the other two patches : > https://patchwork.kernel.org/patch/6989541/ > https://patchwork.kernel.org/patch/6989531/ > > ahb_reset is hreset_n signal of dwc2 IP. Our rk3288 SoC implement > connect this signal to a special > register in clock ang reset unit (CRU) module, set this register will > reset dwc2 control and status registers(CSR) > to default value. You could find more info in <<DesignWare Cores USB 2.0 > Hi Speed On-TheGo (OTG) Databook 3.10a>> > 4.4.1 System Clock and Reset Signals. > > Our problem is that dwc2_get_hwparams() reads fifo size registers and > reguards it as the power-on reset value, > then dwc2_set_param_host_perio_tx_fifo_size() will check this value and > make sure the new fifo size value is no bigger > than the power-on reset value. But we init and set these fifo registers > in BIOS, so here hw->xxx_fifo_size is not the > real power-on reset vaule. So we hope to reset CSR before > dwc2_get_hwparams(). > > I have another ideal: we might use GRSTCTL.CSftRst instead of hreset_n > to reset dwc2 CSR. Yes, please try doing that before calling dwc2_get_hwparams(). Maybe by calling dwc2_core_reset(). If that works for you, I think it would be better. John -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
