[PATCH] media: staging/ipu7: use guard(mutex) and simplify retry loop in buttress

[Laurian Iacob <laurian.iacob@yahoo.com>]

Use scope-based guard(mutex) from linux/cleanup.h in
ipu_buttress_ipc_send_msg() and ipu_buttress_authenticate() to simplify
error handling and remove redundant goto unlock paths.

Additionally, replace the backward goto retry label in
ipu_buttress_ipc_send_msg() with a standard for (;;) loop to improve
control flow readability.

Signed-off-by: Laurian Iacob <laurian.iacob@yahoo.com>
---
 drivers/staging/media/ipu7/ipu7-buttress.c | 56 ++++++++++------------
 1 file changed, 26 insertions(+), 30 deletions(-)

diff --git a/drivers/staging/media/ipu7/ipu7-buttress.c b/drivers/staging/media/ipu7/ipu7-buttress.c
index 40c6c8473357..7ec8290c4432 100644
--- a/drivers/staging/media/ipu7/ipu7-buttress.c
+++ b/drivers/staging/media/ipu7/ipu7-buttress.c
@@ -6,6 +6,7 @@
 #include <asm/cpu_device_id.h>
 #include <linux/bitfield.h>
 #include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
@@ -229,39 +230,39 @@ static int ipu_buttress_ipc_send_msg(struct ipu7_device *isp,
 	u32 val;
 	int ret;
 
-	mutex_lock(&b->ipc_mutex);
+	guard(mutex)(&b->ipc_mutex);
 
 	ret = ipu_buttress_ipc_validity_open(isp, ipc);
 	if (ret) {
 		dev_err(dev, "IPC validity open failed\n");
-		goto out;
+		return ret;
 	}
 
 	tx_timeout_jiffies = msecs_to_jiffies(BUTTRESS_IPC_TX_TIMEOUT_MS);
 	rx_timeout_jiffies = msecs_to_jiffies(BUTTRESS_IPC_RX_TIMEOUT_MS);
 
-try:
-	reinit_completion(&ipc->send_complete);
-	if (msg->require_resp)
-		reinit_completion(&ipc->recv_complete);
+	for (;;) {
+		reinit_completion(&ipc->send_complete);
+		if (msg->require_resp)
+			reinit_completion(&ipc->recv_complete);
 
-	dev_dbg(dev, "IPC command: 0x%x\n", msg->cmd);
-	writel(msg->cmd, isp->base + ipc->data0_out);
-	val = BUTTRESS_IU2CSEDB0_BUSY | msg->cmd_size;
-	writel(val, isp->base + ipc->db0_out);
+		dev_dbg(dev, "IPC command: 0x%x\n", msg->cmd);
+		writel(msg->cmd, isp->base + ipc->data0_out);
+		val = BUTTRESS_IU2CSEDB0_BUSY | msg->cmd_size;
+		writel(val, isp->base + ipc->db0_out);
 
-	tout = wait_for_completion_timeout(&ipc->send_complete,
-					   tx_timeout_jiffies);
-	if (!tout) {
+		tout = wait_for_completion_timeout(&ipc->send_complete,
+						   tx_timeout_jiffies);
+		if (tout)
+			break;
 		dev_err(dev, "send IPC response timeout\n");
-		if (!retry--) {
+		if (retry-- == 0) {
 			ret = -ETIMEDOUT;
 			goto out;
 		}
 
 		/* Try again if CSE is not responding on first try */
 		writel(0, isp->base + ipc->db0_out);
-		goto try;
 	}
 
 	if (!msg->require_resp) {
@@ -852,11 +853,11 @@ int ipu_buttress_authenticate(struct ipu7_device *isp)
 		return 0;
 	}
 
-	mutex_lock(&b->auth_mutex);
+	guard(mutex)(&b->auth_mutex);
 
 	if (ipu_buttress_auth_done(isp)) {
 		ret = 0;
-		goto out_unlock;
+		return 0;
 	}
 
 	/*
@@ -879,7 +880,7 @@ int ipu_buttress_authenticate(struct ipu7_device *isp)
 				    BUTTRESS_CSE2IUDATA0_IPC_BOOT_LOAD_DONE);
 	if (ret) {
 		dev_err(dev, "CSE boot_load failed\n");
-		goto out_unlock;
+		return ret;
 	}
 
 	mask = BUTTRESS_SECURITY_CTL_FW_SETUP_MASK;
@@ -891,13 +892,12 @@ int ipu_buttress_authenticate(struct ipu7_device *isp)
 				 BUTTRESS_CSE_BOOTLOAD_TIMEOUT_US);
 	if (ret) {
 		dev_err(dev, "CSE boot_load timeout\n");
-		goto out_unlock;
+		return ret;
 	}
 
 	if ((data & mask) == fail) {
 		dev_err(dev, "CSE auth failed\n");
-		ret = -EINVAL;
-		goto out_unlock;
+		return -EINVAL;
 	}
 
 	ret = readl_poll_timeout(isp->base + BOOTLOADER_STATUS_OFFSET,
@@ -905,7 +905,7 @@ int ipu_buttress_authenticate(struct ipu7_device *isp)
 				 BUTTRESS_CSE_BOOTLOAD_TIMEOUT_US);
 	if (ret) {
 		dev_err(dev, "Unexpected magic number 0x%x\n", data);
-		goto out_unlock;
+		return ret;
 	}
 
 	/*
@@ -919,7 +919,7 @@ int ipu_buttress_authenticate(struct ipu7_device *isp)
 				    BUTTRESS_CSE2IUDATA0_IPC_AUTH_RUN_DONE);
 	if (ret) {
 		dev_err(dev, "CSE authenticate_run failed\n");
-		goto out_unlock;
+		return ret;
 	}
 
 	done = BUTTRESS_SECURITY_CTL_AUTH_DONE;
@@ -929,21 +929,17 @@ int ipu_buttress_authenticate(struct ipu7_device *isp)
 				 BUTTRESS_CSE_AUTHENTICATE_TIMEOUT_US);
 	if (ret) {
 		dev_err(dev, "CSE authenticate timeout\n");
-		goto out_unlock;
+		return ret;
 	}
 
 	if ((data & mask) == fail) {
 		dev_err(dev, "CSE boot_load failed\n");
-		ret = -EINVAL;
-		goto out_unlock;
+		return -EINVAL;
 	}
 
 	dev_info(dev, "CSE authenticate_run done\n");
 
-out_unlock:
-	mutex_unlock(&b->auth_mutex);
-
-	return ret;
+	return 0;
 }
 
 static int ipu_buttress_send_tsc_request(struct ipu7_device *isp)
-- 
2.43.0