From 47b1be5c0f4ed4991f3d956dbd7ba69cb5bc521f Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Wed, 20 Feb 2013 10:57:01 +0800 Subject: [PATCH] staging: imx/drm: request irq only after adding the crtc If the bootloader already enabled the display, the interrupt handler will be called as soon as it is registered. If the CRTC is not already added at this time, the call to imx_drm_handle_vblank will result in a NULL pointer dereference. The patch fixes a kernel panic [1], which has been on linux-next since Jan 8 [2]. [1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/218858 [2] http://thread.gmane.org/gmane.linux.ports.arm.kernel/208192 Signed-off-by: Philipp Zabel Tested-by: Shawn Guo Signed-off-by: Greg Kroah-Hartman --- drivers/staging/imx-drm/ipuv3-crtc.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/staging/imx-drm/ipuv3-crtc.c b/drivers/staging/imx-drm/ipuv3-crtc.c index 4b3a019409b..b028b0d1317 100644 --- a/drivers/staging/imx-drm/ipuv3-crtc.c +++ b/drivers/staging/imx-drm/ipuv3-crtc.c @@ -483,17 +483,6 @@ static int ipu_get_resources(struct ipu_crtc *ipu_crtc, goto err_out; } - ipu_crtc->irq = ipu_idmac_channel_irq(ipu, ipu_crtc->ipu_ch, - IPU_IRQ_EOF); - ret = devm_request_irq(ipu_crtc->dev, ipu_crtc->irq, ipu_irq_handler, 0, - "imx_drm", ipu_crtc); - if (ret < 0) { - dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret); - goto err_out; - } - - disable_irq(ipu_crtc->irq); - return 0; err_out: ipu_put_resources(ipu_crtc); @@ -504,6 +493,7 @@ err_out: static int ipu_crtc_init(struct ipu_crtc *ipu_crtc, struct ipu_client_platformdata *pdata) { + struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent); int ret; ret = ipu_get_resources(ipu_crtc, pdata); @@ -522,6 +512,17 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc, goto err_put_resources; } + ipu_crtc->irq = ipu_idmac_channel_irq(ipu, ipu_crtc->ipu_ch, + IPU_IRQ_EOF); + ret = devm_request_irq(ipu_crtc->dev, ipu_crtc->irq, ipu_irq_handler, 0, + "imx_drm", ipu_crtc); + if (ret < 0) { + dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret); + goto err_put_resources; + } + + disable_irq(ipu_crtc->irq); + return 0; err_put_resources: -- 2.20.1