imx-drm: imx-drm-core: use array instead of list for CRTCs

The DRM core indexes vblank by number, so there's little point
maintaining a list, and have to scan the list to find the appropriate
structure.  Instead, use an array of pointers to the CRTCs.

Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/staging/imx-drm/imx-drm-core.c b/drivers/staging/imx-drm/imx-drm-core.c
index 92fde89f58ac946cf7909939a0a35dea904817af..c5268847a54e0c0bbec5b8b9c5cbc82beb24afa8 100644 (file)
--- a/drivers/staging/imx-drm/imx-drm-core.c
+++ b/drivers/staging/imx-drm/imx-drm-core.c
@@ -34,10 +34,12 @@ struct crtc_cookie {
        struct list_head list;
 };
 
+struct imx_drm_crtc;
+
 struct imx_drm_device {
        struct drm_device                       *drm;
        struct device                           *dev;
-       struct list_head                        crtc_list;
+       struct imx_drm_crtc                     *crtc[MAX_CRTC];
        struct list_head                        encoder_list;
        struct list_head                        connector_list;
        struct mutex                            mutex;
@@ -47,7 +49,6 @@ struct imx_drm_device {
 
 struct imx_drm_crtc {
        struct drm_crtc                         *crtc;
-       struct list_head                        list;
        struct imx_drm_device                   *imxdrm;
        int                                     pipe;
        struct imx_drm_crtc_helper_funcs        imx_drm_helper_funcs;
@@ -69,6 +70,8 @@ struct imx_drm_connector {
        struct module                           *owner;
 };
 
+static struct imx_drm_device *__imx_drm_device(void);
+
 int imx_drm_crtc_id(struct imx_drm_crtc *crtc)
 {
        return crtc->pipe;
@@ -96,34 +99,28 @@ static int imx_drm_driver_unload(struct drm_device *drm)
        return 0;
 }
 
-/*
- * We don't care at all for crtc numbers, but the core expects the
- * crtcs to be numbered
- */
-static struct imx_drm_crtc *imx_drm_crtc_by_num(struct imx_drm_device *imxdrm,
-               int num)
+struct imx_drm_crtc *imx_drm_find_crtc(struct drm_crtc *crtc)
 {
-       struct imx_drm_crtc *imx_drm_crtc;
+       struct imx_drm_device *imxdrm = __imx_drm_device();
+       unsigned i;
+
+       for (i = 0; i < MAX_CRTC; i++)
+               if (imxdrm->crtc[i] && imxdrm->crtc[i]->crtc == crtc)
+                       return imxdrm->crtc[i];
 
-       list_for_each_entry(imx_drm_crtc, &imxdrm->crtc_list, list)
-               if (imx_drm_crtc->pipe == num)
-                       return imx_drm_crtc;
        return NULL;
 }
 
 int imx_drm_crtc_panel_format_pins(struct drm_crtc *crtc, u32 encoder_type,
                u32 interface_pix_fmt, int hsync_pin, int vsync_pin)
 {
-       struct imx_drm_device *imxdrm = crtc->dev->dev_private;
-       struct imx_drm_crtc *imx_crtc;
        struct imx_drm_crtc_helper_funcs *helper;
+       struct imx_drm_crtc *imx_crtc;
 
-       list_for_each_entry(imx_crtc, &imxdrm->crtc_list, list)
-               if (imx_crtc->crtc == crtc)
-                       goto found;
+       imx_crtc = imx_drm_find_crtc(crtc);
+       if (!imx_crtc)
+               return -EINVAL;
 
-       return -EINVAL;
-found:
        helper = &imx_crtc->imx_drm_helper_funcs;
        if (helper->set_interface_pix_fmt)
                return helper->set_interface_pix_fmt(crtc,
@@ -162,10 +159,9 @@ EXPORT_SYMBOL_GPL(imx_drm_handle_vblank);
 static int imx_drm_enable_vblank(struct drm_device *drm, int crtc)
 {
        struct imx_drm_device *imxdrm = drm->dev_private;
-       struct imx_drm_crtc *imx_drm_crtc;
+       struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[crtc];
        int ret;
 
-       imx_drm_crtc = imx_drm_crtc_by_num(imxdrm, crtc);
        if (!imx_drm_crtc)
                return -EINVAL;
 
@@ -181,9 +177,8 @@ static int imx_drm_enable_vblank(struct drm_device *drm, int crtc)
 static void imx_drm_disable_vblank(struct drm_device *drm, int crtc)
 {
        struct imx_drm_device *imxdrm = drm->dev_private;
-       struct imx_drm_crtc *imx_drm_crtc;
+       struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[crtc];
 
-       imx_drm_crtc = imx_drm_crtc_by_num(imxdrm, crtc);
        if (!imx_drm_crtc)
                return;
 
@@ -510,7 +505,7 @@ int imx_drm_add_crtc(struct drm_crtc *crtc,
 
        imx_drm_crtc->owner = owner;
 
-       list_add_tail(&imx_drm_crtc->list, &imxdrm->crtc_list);
+       imxdrm->crtc[imx_drm_crtc->pipe] = imx_drm_crtc;
 
        *new_crtc = imx_drm_crtc;
 
@@ -533,7 +528,7 @@ int imx_drm_add_crtc(struct drm_crtc *crtc,
        return 0;
 
 err_register:
-       list_del(&imx_drm_crtc->list);
+       imxdrm->crtc[imx_drm_crtc->pipe] = NULL;
        kfree(imx_drm_crtc);
 err_alloc:
 err_busy:
@@ -553,7 +548,7 @@ int imx_drm_remove_crtc(struct imx_drm_crtc *imx_drm_crtc)
 
        drm_crtc_cleanup(imx_drm_crtc->crtc);
 
-       list_del(&imx_drm_crtc->list);
+       imxdrm->crtc[imx_drm_crtc->pipe] = NULL;
 
        drm_mode_group_reinit(imxdrm->drm);
 
@@ -660,14 +655,9 @@ EXPORT_SYMBOL_GPL(imx_drm_encoder_add_possible_crtcs);
 
 int imx_drm_encoder_get_mux_id(struct drm_encoder *encoder)
 {
-       struct imx_drm_device *imxdrm = __imx_drm_device();
-       struct imx_drm_crtc *imx_crtc;
-
-       list_for_each_entry(imx_crtc, &imxdrm->crtc_list, list)
-               if (imx_crtc->crtc == encoder->crtc)
-                       return imx_crtc->mux_id;
+       struct imx_drm_crtc *imx_crtc = imx_drm_find_crtc(encoder->crtc);
 
-       return -EINVAL;
+       return imx_crtc ? imx_crtc->mux_id : -EINVAL;
 }
 EXPORT_SYMBOL_GPL(imx_drm_encoder_get_mux_id);
 
@@ -854,7 +844,6 @@ static int __init imx_drm_init(void)
                return -ENOMEM;
 
        mutex_init(&imx_drm_device->mutex);
-       INIT_LIST_HEAD(&imx_drm_device->crtc_list);
        INIT_LIST_HEAD(&imx_drm_device->connector_list);
        INIT_LIST_HEAD(&imx_drm_device->encoder_list);