Re: [PATCH 1/4] media: dvb/af9015, implement eeprom hashing

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Hei,
Comments below.

On 01/22/2010 05:10 PM, Jiri Slaby wrote:
We read the eeprom anyway for dumping. Switch the dumping to
print_hex_dump_bytes and compute hash above that by
hash = 0;
for (u32 VAL) in (eeprom):
   hash *= GOLDEN_RATIO_PRIME_32
   hash += VAL; // while preserving endinaness

The computation is moved earlier to the flow, namely from
af9015_af9013_frontend_attach to af9015_read_config, so that
we can access the sum in af9015_read_config already.

Signed-off-by: Jiri Slaby<jslaby@xxxxxxx>
Cc: Antti Palosaari<crope@xxxxxx>
Cc: Mauro Carvalho Chehab<mchehab@xxxxxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
---
  drivers/media/dvb/dvb-usb/af9015.c |   65 +++++++++++++++++++++++------------
  drivers/media/dvb/dvb-usb/af9015.h |    1 +
  2 files changed, 44 insertions(+), 22 deletions(-)

diff --git a/drivers/media/dvb/dvb-usb/af9015.c b/drivers/media/dvb/dvb-usb/af9015.c
index a365c05..616b3ba 100644
--- a/drivers/media/dvb/dvb-usb/af9015.c
+++ b/drivers/media/dvb/dvb-usb/af9015.c
@@ -21,6 +21,8 @@
   *
   */

+#include<linux/hash.h>
+
  #include "af9015.h"
  #include "af9013.h"
  #include "mt2060.h"
@@ -553,26 +555,45 @@ exit:
  	return ret;
  }

-/* dump eeprom */
-static int af9015_eeprom_dump(struct dvb_usb_device *d)
+/* hash (and dump) eeprom */
+static int af9015_eeprom_hash(struct usb_device *udev)
  {
-	u8 reg, val;
+	static const unsigned int eeprom_size = 256;
+	unsigned int reg;
+	int ret;
+	u8 val, *eeprom;
+	struct req_t req = {READ_I2C, AF9015_I2C_EEPROM, 0, 0, 1, 1,&val};

-	for (reg = 0; ; reg++) {
-		if (reg % 16 == 0) {
-			if (reg)
-				deb_info(KERN_CONT "\n");
-			deb_info(KERN_DEBUG "%02x:", reg);
-		}
-		if (af9015_read_reg_i2c(d, AF9015_I2C_EEPROM, reg,&val) == 0)
-			deb_info(KERN_CONT " %02x", val);
-		else
-			deb_info(KERN_CONT " --");
-		if (reg == 0xff)
-			break;
+	eeprom = kmalloc(eeprom_size, GFP_KERNEL);
+	if (eeprom == NULL)
+		return -ENOMEM;
+
+	for (reg = 0; reg<  eeprom_size; reg++) {
+		req.addr = reg;
+		ret = af9015_rw_udev(udev,&req);
+		if (ret)
+			goto free;
+		eeprom[reg] = val;
  	}
-	deb_info(KERN_CONT "\n");
-	return 0;
+
+	if (dvb_usb_af9015_debug&  0x01)
+		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, eeprom,
+				eeprom_size);
+
+	BUG_ON(eeprom_size % 4);
+
+	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.

regards
Antti
--
http://palosaari.fi/
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