[PATCH AUTOSEL 5.1 18/51] drm/mediatek: clear num_pipes when unbind driver

[Sasha Levin]

From: Hsin-Yi Wang <hsinyi at chromium.org>

[ Upstream commit a4cd1d2b016d5d043ab2c4b9c4ec50a5805f5396 ]

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 at chromium.org>
Signed-off-by: CK Hu <ck.hu at mediatek.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 8718d123ccaa..bbfe3a464aea 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -400,6 +400,7 @@ static void mtk_drm_unbind(struct device *dev)
 	drm_dev_unregister(private->drm);
 	mtk_drm_kms_deinit(private->drm);
 	drm_dev_put(private->drm);
+	private->num_pipes = 0;
 	private->drm = NULL;
 }
 
-- 
2.20.1