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Message-Id: <1477945112-25659-4-git-send-email-linux@rainbow-software.org>
Date: Mon, 31 Oct 2016 21:18:29 +0100
From: Ondrej Zary <linux@...nbow-software.org>
To: Christoph Hellwig <hch@...radead.org>
Cc: Finn Thain <fthain@...egraphics.com.au>,
linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 3/6] g_NCR5380: Check for chip presence before calling NCR5380_init()
Write and read back MODE_REG to check if the chip is really there
before doing more initialization.
This prevents hang when incorrect I/O address was specified by user (in
the most common case where no device is present there so all reads
result in 0xff).
Signed-off-by: Ondrej Zary <linux@...nbow-software.org>
---
drivers/scsi/g_NCR5380.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index 0d1f6ad..e713dba 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -322,6 +322,13 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt,
}
}
+ /* check if the chip is really there */
+ NCR5380_write(MODE_REG, 0);
+ if (NCR5380_read(MODE_REG) != 0) {
+ ret = -ENODEV;
+ goto out_unregister;
+ }
+
ret = NCR5380_init(instance, flags | FLAG_LATE_DMA_SETUP);
if (ret)
goto out_unregister;
--
Ondrej Zary
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