From:   Wei Yongjun <weiyongjun1@huawei.com>
To:     Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Stefan Roese <sr@denx.de>, Ming Lei <ming.lei@canonical.com>,
        Grant Likely <grant.likely@secretlab.ca>,
        <linux-kernel@vger.kernel.org>
CC:     Wei Yongjun <weiyongjun1@huawei.com>,
        Hulk Robot <hulkci@huawei.com>
Subject: [PATCH] misc: lattice-ecp3-config: Fix task hung when firmware load failed
Date:   Tue, 28 Dec 2021 12:55:22 +0000
Message-ID: <20211228125522.3122284-1-weiyongjun1@huawei.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7BIT
Content-Type:   text/plain; charset=US-ASCII
Precedence: bulk

When firmware load failed, kernel report task hung as follows:

INFO: task xrun:5191 blocked for more than 147 seconds.
      Tainted: G        W         5.16.0-rc5-next-20211220+ #11
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:xrun            state:D stack:    0 pid: 5191 ppid:   270 flags:0x00000004
Call Trace:
 __schedule+0xc12/0x4b50 kernel/sched/core.c:4986
 schedule+0xd7/0x260 kernel/sched/core.c:6369 (discriminator 1)
 schedule_timeout+0x7aa/0xa80 kernel/time/timer.c:1857
 wait_for_completion+0x181/0x290 kernel/sched/completion.c:85
 lattice_ecp3_remove+0x32/0x40 drivers/misc/lattice-ecp3-config.c:221
 spi_remove+0x72/0xb0 drivers/spi/spi.c:409

lattice_ecp3_remove() wait for signals from firmware loading, but when
load failed, firmware_load() does not send this signal. This cause
device remove hung. Fix it by sending signal even if load failed.

Fixes: 781551df57c7 ("misc: Add Lattice ECP3 FPGA configuration via SPI")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

diff --git a/drivers/misc/lattice-ecp3-config.c b/drivers/misc/lattice-ecp3-config.c
index 0f54730c7ed5..98828030b5a4 100644
--- a/drivers/misc/lattice-ecp3-config.c
+++ b/drivers/misc/lattice-ecp3-config.c
@@ -76,12 +76,12 @@ static void firmware_load(const struct firmware *fw, void *context)
 
 	if (fw == NULL) {
 		dev_err(&spi->dev, "Cannot load firmware, aborting\n");
-		return;
+		goto out;
 	}
 
 	if (fw->size == 0) {
 		dev_err(&spi->dev, "Error: Firmware size is 0!\n");
-		return;
+		goto out;
 	}
 
 	/* Fill dummy data (24 stuffing bits for commands) */
@@ -103,7 +103,7 @@ static void firmware_load(const struct firmware *fw, void *context)
 		dev_err(&spi->dev,
 			"Error: No supported FPGA detected (JEDEC_ID=%08x)!\n",
 			jedec_id);
-		return;
+		goto out;
 	}
 
 	dev_info(&spi->dev, "FPGA %s detected\n", ecp3_dev[i].name);
@@ -116,7 +116,7 @@ static void firmware_load(const struct firmware *fw, void *context)
 	buffer = kzalloc(fw->size + 8, GFP_KERNEL);
 	if (!buffer) {
 		dev_err(&spi->dev, "Error: Can't allocate memory!\n");
-		return;
+		goto out;
 	}
 
 	/*
@@ -155,7 +155,7 @@ static void firmware_load(const struct firmware *fw, void *context)
 			"Error: Timeout waiting for FPGA to clear (status=%08x)!\n",
 			status);
 		kfree(buffer);
-		return;
+		goto out;
 	}
 
 	dev_info(&spi->dev, "Configuring the FPGA...\n");
@@ -181,7 +181,7 @@ static void firmware_load(const struct firmware *fw, void *context)
 	release_firmware(fw);
 
 	kfree(buffer);
-
+out:
 	complete(&data->fw_loaded);
 }
 
-- 
2.25.1