On Wed, 16 Nov 2011 14:35:00 +0530 Varun Wadekar <vwadekar@xxxxxxxxxx> wrote: > > > it's not - it saves writes. > > Are you ok with this solution? Either way I wan to start with a clear > key table before programming the hardware. the hardware doesn't care. > > why do you need to clear the entire key table if it will be > > overwritten anyway? > > If you set a > 128-bit key and then set a 128-bit key, the remaining > bits still remain in the key table. Similarly, if we use updated IV in > one operation and want to use the initial IV for the next, the updated > IV will still remain in the key table. The entire key table is copied to > the AES engine. Even though, we program the engine with the exact number > of bits to use for the key and whether to use the updated/initial IV, I > feel its better if the unused bits are zero instead of having garbage. you're losing free performance. Kim -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
