From a4cd1d2b016d5d043ab2c4b9c4ec50a5805f5396 Mon Sep 17 00:00:00 2001
From: Hsin-Yi Wang <hsinyi@chromium.org>
Date: Wed, 29 May 2019 18:25:55 +0800
Subject: drm/mediatek: clear num_pipes when unbind driver
Git-commit: a4cd1d2b016d5d043ab2c4b9c4ec50a5805f5396
Patch-mainline: v5.2-rc5
References: bsc#1111666 bsc#1135642

num_pipes is used for mutex created in mtk_drm_crtc_create(). If we
don't clear num_pipes count, when rebinding driver, the count will
be accumulated. From mtk_disp_mutex_get(), there can only be at most
10 mutex id. Clear this number so it starts from 0 in every rebind.

Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/mediatek/mtk_drm_drv.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -351,6 +351,7 @@ static void mtk_drm_unbind(struct device
 	drm_dev_unregister(private->drm);
 	mtk_drm_kms_deinit(private->drm);
 	drm_dev_put(private->drm);
+	private->num_pipes = 0;
 	private->drm = NULL;
 }