[meta-freescale] [PATCH 0/1] arm: imx: fsl_otp: make fuses (OTP memory) read-only

Eric Bénard eric at eukrea.com
Fri Nov 7 06:00:03 PST 2014

Hi Alexander,

Le Fri,  7 Nov 2014 10:43:34 +0100,
Alexander Holler <holler at ahsoftware.de> a écrit :
> Jon Nettleton made me aware that there is a driver which makes it very
> easy to write to the OTP from userspace.
> And I have to admit that I was mildly shocked.
> Because OTP stands for One Time Programmable, it means the write
> functionality of that driver can be used only once per HW and if that
> is done wrong, the HW might be one of those famous electronic bricks
> afterwards.
> So I've quickly written a patch which makes this driver to a friendly
> citizen instead of an heavily armed cowboy.
> I really, really think this patch should be attached to all trees which
> are including fsl_otp.c. It applies without any error to
> imx_3.10.17_1.0.1_ga, imx_3.10.31_1.1.0_beta, linux-linaro-lsk-v3.14-mx6
> and likely any other tree which includes that driver.
That's not shocking to have this feature in a reference design's BSP : 
Freescale provides base source code to evaluate their SOC and writing
OTP is one feature of their SOC.
Then that's the end product designer's responsibility to enable/disable
features he wants or not on its product.

The solution proposed by Otavio to add an option to ease the
disabling of this feature is far better than fully removing the code.

Best regards,

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