diff options
| author | Christian Lamparter <chunkeey@googlemail.com> | 2010-08-17 01:16:58 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2010-08-24 16:28:15 -0400 |
| commit | d7eb50c0f7cb5d3ebb7bea8c681a6dfda3819a3b (patch) | |
| tree | b7b03ffbae065955211cced45027672d520442d1 | |
| parent | b9c066597fdf38b126d2e0434d0ce18d22bbf401 (diff) | |
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: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | drivers/net/wireless/p54/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/net/wireless/p54/eeprom.c | 21 |
2 files changed, 19 insertions, 3 deletions
diff --git a/drivers/net/wireless/p54/Kconfig b/drivers/net/wireless/p54/Kconfig index b0342a520bf1..60a930e45a8b 100644 --- a/drivers/net/wireless/p54/Kconfig +++ b/drivers/net/wireless/p54/Kconfig @@ -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 diff --git a/drivers/net/wireless/p54/eeprom.c b/drivers/net/wireless/p54/eeprom.c index d687cb7f2a59..32d3f99b0844 100644 --- a/drivers/net/wireless/p54/eeprom.c +++ b/drivers/net/wireless/p54/eeprom.c @@ -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; } - entry = (void *)entry + (entry_len + 1)*2; + 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, |