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From: Ondrej Zary <linux@rainbow-software.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: Finn Thain <fthain@telegraphics.com.au>,
	linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/3] NCR5380: Check for chip presence in NCR5380_init()
Date: Sun, 30 Oct 2016 23:40:03 +0100	[thread overview]
Message-ID: <1477867203-7480-3-git-send-email-linux@rainbow-software.org> (raw)
In-Reply-To: <1477867203-7480-1-git-send-email-linux@rainbow-software.org>

Read back MODE_REG after writing it in NCR5380_init() to check if the
chip is really there.

This prevents hang when incorrect I/O address was specified by user.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
---
 drivers/scsi/NCR5380.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 01c0027..ce3156d 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -495,6 +495,11 @@ static int NCR5380_init(struct Scsi_Host *instance, int flags)
 
 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
 	NCR5380_write(MODE_REG, MR_BASE);
+	/* check if the chip is really there */
+	if (NCR5380_read(MODE_REG) != MR_BASE) {
+		NCR5380_exit(instance);
+		return -ENODEV;
+	}
 	NCR5380_write(TARGET_COMMAND_REG, 0);
 	NCR5380_write(SELECT_ENABLE_REG, 0);
 
-- 
Ondrej Zary

  parent reply	other threads:[~2016-10-30 22:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-30 22:40 [PATCH 1/3] NCR5380: Use probe_irq_*() for IRQ probing Ondrej Zary
2016-10-30 22:40 ` [PATCH 2/3] g_NCR5380: Test the IRQ before accepting it Ondrej Zary
2016-10-31  3:09   ` Finn Thain
2016-10-31  8:35     ` Ondrej Zary
2016-10-31  9:46       ` Finn Thain
2016-10-30 22:40 ` Ondrej Zary [this message]
2016-10-31  3:12   ` [PATCH 3/3] NCR5380: Check for chip presence in NCR5380_init() Finn Thain
2016-10-31  7:59     ` Ondrej Zary
2016-10-31  9:35       ` Finn Thain
2016-10-31  3:29   ` Finn Thain
2016-10-31  3:07 ` [PATCH 1/3] NCR5380: Use probe_irq_*() for IRQ probing Finn Thain
2016-10-31  8:11   ` Ondrej Zary
2016-10-31  9:40     ` Finn Thain

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