On 01/24/2010 06:35 PM, Jiri Slaby wrote:
On 01/24/2010 05:16 PM, Antti Palosaari wrote:
+    af9015_config.eeprom_sum = 0;
+    for (reg = 0; reg<   eeprom_size / sizeof(u32); reg++) {
+        af9015_config.eeprom_sum *= GOLDEN_RATIO_PRIME_32;
+        af9015_config.eeprom_sum += le32_to_cpu(((u32 *)eeprom)[reg]);
+    }
+
+    deb_info("%s: eeprom sum=%.8x\n", __func__,
af9015_config.eeprom_sum);

Does this sum contain all 256 bytes from EEPROM? 256/4 is 64.

Yes it does. It is computed as a hashed sum of 32-bit numbers (4 bytes)
-- speed (does not matter) and larger space of hashes. Hence the
division by 4. The cast does the trick: ((u32 *)eeprom)[reg] -- reg
index is on a 4-byte basis.


OK, true. Anyhow, I don't know if this hashing formula is good enough - changing it later could be really pain. I compared it to the one used for em28xx driver and it was different. Could someone with better knowledge check that?

Generally it is good and ready for submission.

Acked-by: Antti Palosaari <cr...@iki.fi>

regards
Antti
--
http://palosaari.fi/
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to