imx-drm: ipu-v3: fix potential CRTC device registration race

Clean up the IPUv3 CRTC device registration; we don't need a separate
function just to call platform_device_register_data(), and we don't
need the return value converted at all.

Update the IPU client id under a mutex, so that parallel probing
doesn't race.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/imx-drm/ipu-v3/ipu-common.c b/drivers/staging/imx-drm/ipu-v3/ipu-common.c
index 7a22ce619ed264ba536de785650700b02f6d3ef3..97ca6924dbb3fce7b5db813aefb781adb273187a 100644 (file)
--- a/drivers/staging/imx-drm/ipu-v3/ipu-common.c
+++ b/drivers/staging/imx-drm/ipu-v3/ipu-common.c
@@ -996,35 +996,35 @@ static const struct ipu_platform_reg client_reg[] = {
        },
 };
 
+static DEFINE_MUTEX(ipu_client_id_mutex);
 static int ipu_client_id;
 
-static int ipu_add_subdevice_pdata(struct device *dev,
-               const struct ipu_platform_reg *reg)
-{
-       struct platform_device *pdev;
-
-       pdev = platform_device_register_data(dev, reg->name, ipu_client_id++,
-                       &reg->pdata, sizeof(struct ipu_platform_reg));
-
-       return PTR_ERR_OR_ZERO(pdev);
-}
-
 static int ipu_add_client_devices(struct ipu_soc *ipu)
 {
-       int ret;
-       int i;
+       struct device *dev = ipu->dev;
+       unsigned i;
+       int id, ret;
+
+       mutex_lock(&ipu_client_id_mutex);
+       id = ipu_client_id;
+       ipu_client_id += ARRAY_SIZE(client_reg);
+       mutex_unlock(&ipu_client_id_mutex);
 
        for (i = 0; i < ARRAY_SIZE(client_reg); i++) {
                const struct ipu_platform_reg *reg = &client_reg[i];
-               ret = ipu_add_subdevice_pdata(ipu->dev, reg);
-               if (ret)
+               struct platform_device *pdev;
+
+               pdev = platform_device_register_data(dev, reg->name,
+                       id++, &reg->pdata, sizeof(reg->pdata));
+
+               if (IS_ERR(pdev))
                        goto err_register;
        }
 
        return 0;
 
 err_register:
-       platform_device_unregister_children(to_platform_device(ipu->dev));
+       platform_device_unregister_children(to_platform_device(dev));
 
        return ret;
 }