From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH v7 1/5] usb: dwc3: omap: use request_threaded_irq() Date: Wed, 11 May 2016 16:52:34 +0300 Message-ID: <57333922.1010003@ti.com> References: <1462873919-20532-1-git-send-email-rogerq@ti.com> <1462873919-20532-2-git-send-email-rogerq@ti.com> <87a8jyi6ad.fsf@linux.intel.com> <5731B235.80505@ti.com> <87y47igr1g.fsf@linux.intel.com> <5732EA85.6050601@ti.com> <87y47hexja.fsf@linux.intel.com> <57331B85.2000003@ti.com> <87r3d8g44i.fsf@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <87r3d8g44i.fsf@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Felipe Balbi Cc: tony@atomide.com, Joao.Pinto@synopsys.com, sergei.shtylyov@cogentembedded.com, peter.chen@freescale.com, jun.li@freescale.com, grygorii.strashko@ti.com, yoshihiro.shimoda.uh@renesas.com, nsekhar@ti.com, b-liu@ti.com, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-omap@vger.kernel.org On 11/05/16 15:39, Felipe Balbi wrote: > > Hi, > > Roger Quadros writes: >>>>> static irqreturn_t dwc3_omap_threaded_interrupt(int irq, void *_omap) >>>>> { >>>>> struct dwc3_omap *omap = _omap; >>>>> u32 reg; >>>>> >>>>> spin_lock(&omap->lock); >>>> >>>> Do we really need a spin_lock for the dwc3-omap driver? >>>> Currently we won't be doing anything other than just >>>> clearing the irqstatus and re-enabling the interrupts. >>> >>> well, if there's no possibility of races, then no. But only testing will >>> say for sure, I guess. I didn't really go through the entire thing just >>> to a write a quick little template :-p >>> >> OK. Another hurdle I have is that how do I mask/unmask the interrupts? >> I do not see any masking bits, only enable/disable bits. >> >> I don't think we can use the enable/disable bits to mask as we'd loose >> events while the event is disabled. > > I'm pretty sure your TRM discusses the usage of IRQSTATUS_RAW* > registers, doesn't it ? :-) It does and also says that it is mostly for debug. But I don't mind using it if it solves our problem :). > > Those registers should be modified by HW even when interrupts are > disabled/masked. Note that, the IRQSTATUS_SET* and IRQSTATUS_CLR* > registers act more like mask/unmask than enable/disable considering we > can still read IRQ status using *RAW* registers. > > See if below works fine for OMAP5, AM4 and AM5 SoCs: > > diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c > index af264493bbae..ece2f25ad2c3 100644 > --- a/drivers/usb/dwc3/dwc3-omap.c > +++ b/drivers/usb/dwc3/dwc3-omap.c > @@ -165,20 +165,20 @@ static void dwc3_omap_write_utmi_ctrl(struct dwc3_omap *omap, u32 value) > > static u32 dwc3_omap_read_irq0_status(struct dwc3_omap *omap) > { > - return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_0 - > + return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_RAW_0 - > omap->irq0_offset); > } > > static void dwc3_omap_write_irq0_status(struct dwc3_omap *omap, u32 value) > { > - dwc3_omap_writel(omap->base, USBOTGSS_IRQSTATUS_0 - > + dwc3_omap_writel(omap->base, USBOTGSS_IRQSTATUS_RAW_0 - > omap->irq0_offset, value); We shouldn't write to RAW here as it will trigger a software IRQ instead of clearing the event. > > } > > static u32 dwc3_omap_read_irqmisc_status(struct dwc3_omap *omap) > { > - return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_MISC + > + return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_RAW_MISC + > omap->irqmisc_offset); > } > > The rest is fine. It seemed to work on omap5. I'll do more tests though. Thanks for the hint :) cheers, -roger