> -----Original Message----- > From: Zhangfei Gao [mailto:zhangfei....@linaro.org] > Sent: Thursday, February 5, 2015 3:22 AM > To: Kaukab, Yousaf > Cc: ba...@ti.com; john.y...@synopsys.com; linux-usb@vger.kernel.org > Subject: Re: [PATCH 2/2] usb: dwc2: gadget reuse ahbcfg assigned from > platform > > Hi Yousaf > > On 4 February 2015 at 17:41, Kaukab, Yousaf <yousaf.kau...@intel.com> > wrote: > >> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c index > >> d5197d4..8d388cc 100644 > >> --- a/drivers/usb/dwc2/core.c > >> +++ b/drivers/usb/dwc2/core.c > >> @@ -2563,7 +2563,7 @@ void dwc2_set_param_reload_ctl(struct > >> dwc2_hsotg *hsotg, int val) > >> > >> void dwc2_set_param_ahbcfg(struct dwc2_hsotg *hsotg, int val) { > >> - if (val != -1) > >> + if (val) > >> hsotg->core_params->ahbcfg = val; > >> else > >> hsotg->core_params->ahbcfg = > >> GAHBCFG_HBSTLEN_INCR4 << diff --git a/drivers/usb/dwc2/gadget.c > >> b/drivers/usb/dwc2/gadget.c index 15aa578..20085de 100644 > >> --- a/drivers/usb/dwc2/gadget.c > >> +++ b/drivers/usb/dwc2/gadget.c > >> @@ -2314,9 +2314,13 @@ void s3c_hsotg_core_init_disconnected(struct > >> dwc2_hsotg *hsotg, > >> GINTSTS_USBSUSP | GINTSTS_WKUPINT, > >> hsotg->regs + GINTMSK); > >> > >> + if ((hsotg->core_params) && (hsotg->core_params->ahbcfg != - > >> 1)) > >> + val = hsotg->core_params->ahbcfg & > >> ~GAHBCFG_CTRL_MASK; > >> + else > >> + val = GAHBCFG_HBSTLEN_INCR4 << > >> GAHBCFG_HBSTLEN_SHIFT; > >> + > >> if (using_dma(hsotg)) > >> - writel(GAHBCFG_GLBL_INTR_EN | > >> GAHBCFG_DMA_EN | > >> - (GAHBCFG_HBSTLEN_INCR4 << > >> GAHBCFG_HBSTLEN_SHIFT), > >> + writel(GAHBCFG_GLBL_INTR_EN | > >> GAHBCFG_DMA_EN | val, > >> hsotg->regs + GAHBCFG); > >> else > >> writel(((hsotg->dedicated_fifos) ? > >> (GAHBCFG_NP_TXF_EMP_LVL | > > > > There are other bits in GAHBCFG that can be set from platform. They will be > preserved by your patch, as they are not part of GAHBCFG_CTRL_MASK, but > only in case dma is enabled. Perhaps preserve them in non-dma case as well. > > Here may have issue if also set hsotg->core_params->ahbcfg for non-dma case, > since GAHBCFG[4:1] may be set.
You can mask off HBstLen in that case. However, I don't think setting burst length will be an issue in non DMA case as DWC2 will not act as a bus master. John, can you please confirm if setting burst length will be an issue in non-dma case? > > Though from drivers/usb/dwc2/core.h we can not see @ahbcfg is specifically > used for dma case, most case in drivers/usb/dwc2/platform.c use ahbcfg is set > hbstlen, GAHBCFG[4:1]. > For example, our platform set GAHBCFG_HBSTLEN_INCR16. > > So I just assume @ahbcfg is used for dma case. > What do you think. While you are fixing it, why not fix it for other bits, for example AHBSingle, InvDescEndianness etc., which are part of the same register and will be overwritten at the same place. > > Thanks BR, Yousaf
