From mboxrd@z Thu Jan 1 00:00:00 1970 From: marex@denx.de (Marek Vasut) Date: Tue, 8 Jan 2013 18:09:38 +0100 Subject: [PATCH 7/7] ARM i.MX51 babbage: Add display support In-Reply-To: References: <1352733809-27230-1-git-send-email-s.hauer@pengutronix.de> Message-ID: <201301081809.38537.marex@denx.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Dear Fabio Estevam, > On Tue, Jan 8, 2013 at 2:41 PM, Fabio Estevam wrote: > > Hi Sascha, > > > > On Mon, Nov 12, 2012 at 1:23 PM, Sascha Hauer wrote: > >> The babbage board has a DVI-I output which allows to output analog > >> and digital signals simultaneously. This patch adds support for it > >> to the devicetree. The DDC signals are not wired up on the board, so > >> DRM will fall back on default VESA modes. > >> > >> Signed-off-by: Sascha Hauer > > > > I am running linux-next 20130108, which has this patch applied and I > > > get the following on my mx51babbage: > Ok, good news. I see a nice penguin on my monitor now. > > Discussed with Marek and he proposed a quick workaround: > > --- a/drivers/staging/imx-drm/ipuv3-crtc.c > +++ b/drivers/staging/imx-drm/ipuv3-crtc.c > @@ -343,6 +343,11 @@ static irqreturn_t ipu_irq_handler(int irq, void > *dev_id) { > struct ipu_crtc *ipu_crtc = dev_id; > > + if (!ipu_crtc->imx_crtc) { > + pr_err("Spurious IPU IRQ\n"); > + return IRQ_HANDLED; > + } > + > imx_drm_handle_vblank(ipu_crtc->imx_crtc); > > if (ipu_crtc->newfb) { > > It seems that this issue happened because bootloader leaves the IPU turned > on. To elaborate more on this stuff: 491 ipu_crtc->irq = ipu_idmac_channel_irq(ipu, ipu_crtc->ipu_ch, 492 IPU_IRQ_EOF); 493 ret = devm_request_irq(ipu_crtc->dev, ipu_crtc->irq, ipu_irq_handler, 0, 494 "imx_drm", ipu_crtc); 495 if (ret < 0) { 496 dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret); 497 goto err_out; 498 } 499 500 disable_irq(ipu_crtc->irq); This code in drivers/staging/imx-drm/ipuv3-crtc.c is broken. If the IPU is on, it produces an interrupt before the driver is fully set up. I didn't produce a patch yet, I think I might offload this to someone else. Volunteers? Best regards, Marek Vasut