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Sender: Peter Korsgaard <jacmet@gmail.com>
From: Peter Korsgaard <jacmet@sunsite.dk>
To: Daniel Mack <zonque@gmail.com>
Subject: Re: [PATCH] mtd: devices: elm: check for device's presence before
 configuration
References: <1362345178-12536-1-git-send-email-zonque@gmail.com>
Date: Sun, 03 Mar 2013 22:44:05 +0100
In-Reply-To: <1362345178-12536-1-git-send-email-zonque@gmail.com> (Daniel
 Mack's message of "Sun, 3 Mar 2013 22:12:58 +0100")
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Cc: dwmw2@infradead.org, linux-mtd@lists.infradead.org,
 Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
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>>>>> "Daniel" == Daniel Mack <zonque@gmail.com> writes:

 Daniel> In case the driver is not probed - due to config mismatches or errors
 Daniel> in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops
 Daniel> during boot. Better bail out with a warning in such cases.

 Daniel> Signed-off-by: Daniel Mack <zonque@gmail.com>
 Daniel> Cc: Philip Avinash <avinashphilip@ti.com>
 Daniel> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
 Daniel> ---
 Daniel>  drivers/mtd/devices/elm.c | 5 +++++
 Daniel>  1 file changed, 5 insertions(+)

 Daniel> diff --git a/drivers/mtd/devices/elm.c b/drivers/mtd/devices/elm.c
 Daniel> index 2ec5da9..a9b6d04 100644
 Daniel> --- a/drivers/mtd/devices/elm.c
 Daniel> +++ b/drivers/mtd/devices/elm.c
 Daniel> @@ -86,6 +86,11 @@ void elm_config(struct device *dev, enum bch_ecc bch_type)
 Daniel>  	u32 reg_val;
 Daniel>  	struct elm_info *info = dev_get_drvdata(dev);
 
 Daniel> +	if (!info) {
 Daniel> +		dev_err(dev, "Unable to configure elm - device not probed?\n");
 Daniel> +		return;
 Daniel> +	}
 Daniel> +

Even better would be to propagate the error message (E.G. return
-ENODEV) and let omap2.c deal with it (fall back to sw).

-- 
Bye, Peter Korsgaard