[PATCH 2/2] imx-drm: ipuv3-plane: fix kernel Oops in ipu_dp_put()
From: p.zabel@pengutronix.de (Philipp Zabel)
Date: 2014-08-19 13:59:38
Also in:
dri-devel
Subsystem:
staging subsystem, the rest · Maintainers:
Greg Kroah-Hartman, Linus Torvalds
Hi Shawn, Am Dienstag, den 19.08.2014, 17:49 +0800 schrieb Shawn Guo:
Unbinding imx-hdmi or imx-ldb driver triggers a kernel Oops in function ipu_dp_put() as below. $ echo 120000.hdmi > /sys/devices/soc0/soc/2000000.aips-bus/120000.hdmi/driver/unbind
[...]
quoted hunk ↗ jump to hunk
From the call stack, the issue is caused by that ipu_dp_put() is called from ipu_plane_dpms() with ipu_plane->dp being NULL. Rather than being called unconditionally, ipu_dp_put() should be called only when ipu_plane->dp is valid, just like what ipu_plane_put_resources() does. Acutally, all those ipu_*_put() calls in ipu_plane_dpms() are unnecessary, because the only occurrence of ipu_plane_dpms() with 'mode' not being DRM_MODE_DPMS_ON is from function ipu_disable_plane(), which already has a ipu_plane_put_resources() call right after ipu_plane_dpms(). The patch fixes above kernel Oops by removing those buggy and unnecessary ipu_*_put() calls from ipu_plane_dpms(). Signed-off-by: Shawn Guo <redacted> --- drivers/staging/imx-drm/ipuv3-plane.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)diff --git a/drivers/staging/imx-drm/ipuv3-plane.c b/drivers/staging/imx-drm/ipuv3-plane.c index 6f393a11f44d..a79ae7731a03 100644 --- a/drivers/staging/imx-drm/ipuv3-plane.c +++ b/drivers/staging/imx-drm/ipuv3-plane.c@@ -274,15 +274,10 @@ static void ipu_plane_dpms(struct ipu_plane *ipu_plane, int mode) if (enable == ipu_plane->enabled) return; - if (enable) { + if (enable) ipu_plane_enable(ipu_plane); - } else { + else ipu_plane_disable(ipu_plane); - - ipu_idmac_put(ipu_plane->ipu_ch); - ipu_dmfc_put(ipu_plane->dmfc); - ipu_dp_put(ipu_plane->dp); - } } /*
we could then remove ipu_plane_dpms completely: --- drivers/staging/imx-drm/ipuv3-plane.c | 23 ++++------------------- 1 file changed, 4 insertions(+), 19 deletions(-)
diff --git a/drivers/staging/imx-drm/ipuv3-plane.c b/drivers/staging/imx-drm/ipuv3-plane.c
index b2d1bb2..6987e16 100644
--- a/drivers/staging/imx-drm/ipuv3-plane.c
+++ b/drivers/staging/imx-drm/ipuv3-plane.c@@ -290,23 +290,6 @@ void ipu_plane_disable(struct ipu_plane *ipu_plane) ipu_dp_disable(ipu_plane->ipu); } -static void ipu_plane_dpms(struct ipu_plane *ipu_plane, int mode) -{ - bool enable; - - DRM_DEBUG_KMS("mode = %d", mode); - - enable = (mode == DRM_MODE_DPMS_ON); - - if (enable == ipu_plane->enabled) - return; - - if (enable) - ipu_plane_enable(ipu_plane); - else - ipu_plane_disable(ipu_plane); -} - /* * drm_plane API */
@@ -340,7 +323,8 @@ static int ipu_update_plane(struct drm_plane *plane, struct drm_crtc *crtc, plane->crtc, crtc); plane->crtc = crtc; - ipu_plane_dpms(ipu_plane, DRM_MODE_DPMS_ON); + if (!ipu_plane->enabled) + ipu_plane_enable(ipu_plane); return 0; }
@@ -351,7 +335,8 @@ static int ipu_disable_plane(struct drm_plane *plane) DRM_DEBUG_KMS("[%d] %s\n", __LINE__, __func__); - ipu_plane_dpms(ipu_plane, DRM_MODE_DPMS_OFF); + if (ipu_plane->enabled) + ipu_plane_disable(ipu_plane); ipu_plane_put_resources(ipu_plane);
--
2.1.0.rc1
regards
Philipp