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Commit d7eb50c0 authored by Christian Lamparter's avatar Christian Lamparter Committed by John W. Linville
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p54: improve eeprom parser 

Like other vendors, p54* devices have a checksum for
the EEPROM descriptor data. This patch enhances the
parser code to generate and verify the data fields,
before initializing the radio-chip on the card.

Note:
	If you have to bootstrap an alternative EEPROM image
	for your device and you don't know how to generate a
	valid crc ccitt checksum, you should take a look at:
	http://git.kernel.org/?p=linux/kernel/git/chr/p54tools.git



	The "checksum" utility loads a binary p54 EEPROM blob
	(use the -f switch, to skip the check) and applies
	the correct crc automatically.

Signed-off-by: default avatarChristian Lamparter <chunkeey@googlemail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent b9c06659

drivers/net/wireless/p54/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ config P54_COMMON 
	tristate "Softmac Prism54 support"

	depends on MAC80211 && EXPERIMENTAL

	select FW_LOADER

	select CRC_CCITT

	---help---

	  This is common code for isl38xx/stlc45xx based modules.

	  This module does nothing by itself - the USB/PCI/SPI front-ends

drivers/net/wireless/p54/eeprom.c

+18 −3
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/slab.h>



#include <net/mac80211.h>

#include <linux/crc-ccitt.h>



#include "p54.h"

#include "eeprom.h"
@@ -540,6 +541,7 @@ int p54_parse_eeprom(struct ieee80211_hw *dev, void *eeprom, int len) 
	int err;

	u8 *end = (u8 *)eeprom + len;

	u16 synth = 0;

	u16 crc16 = ~0;



	wrap = (struct eeprom_pda_wrap *) eeprom;

	entry = (void *)wrap->data + le16_to_cpu(wrap->len);
@@ -655,16 +657,29 @@ int p54_parse_eeprom(struct ieee80211_hw *dev, void *eeprom, int len) 
			}

			break;

		case PDR_END:

			/* make it overrun */

			entry_len = len;

			crc16 = ~crc_ccitt(crc16, (u8 *) entry, sizeof(*entry));

			if (crc16 != le16_to_cpup((__le16 *)entry->data)) {

				wiphy_err(dev->wiphy, "eeprom failed checksum "

					 "test!\n");

				err = -ENOMSG;

				goto err;

			} else {

				goto good_eeprom;

			}

			break;

		default:

			break;

		}



		crc16 = crc_ccitt(crc16, (u8 *)entry, (entry_len + 1) * 2);

		entry = (void *)entry + (entry_len + 1) * 2;

	}



	wiphy_err(dev->wiphy, "unexpected end of eeprom data.\n");

	err = -ENODATA;

	goto err;



good_eeprom:

	if (!synth || !priv->iq_autocal || !priv->output_limit ||

	    !priv->curve_data) {

		wiphy_err(dev->wiphy,