diff options
| author | Ivo van Doorn <ivdoorn@gmail.com> | 2008-02-03 15:48:38 +0100 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2008-02-29 15:19:28 -0500 |
| commit | 9404ef34e4747228717d6e22ce3827ed366ccf41 (patch) | |
| tree | 90f4a51af46519e42dcd638a3344ee664db539ec /drivers/net/wireless/rt2x00/rt2x00firmware.c | |
| parent | adfdbb79c06154cd3cc7b5983106ace324aa3b02 (diff) | |
rt2x00: Driver requiring firmware should select crc algo
The driver should select what CRC algorithm is required
when performing a checksum on the firmware.
rt61pci & rt73usb require crc-itu-t
rt2800pci & rt2800usb require crc-ccitt
Legacy 2800pci/usb driver uses crc-itu-t + bit order reversion,
but that is just inefficient especially since the end result is
the same as a different algorithm which is also available as library. ;)
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2x00firmware.c')
| -rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00firmware.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2x00firmware.c b/drivers/net/wireless/rt2x00/rt2x00firmware.c index 442ff8047dce..4f9fe56f4f2e 100644 --- a/drivers/net/wireless/rt2x00/rt2x00firmware.c +++ b/drivers/net/wireless/rt2x00/rt2x00firmware.c @@ -23,6 +23,7 @@ Abstract: rt2x00 firmware loading routines. */ +#include <linux/crc-ccitt.h> #include <linux/crc-itu-t.h> #include <linux/kernel.h> #include <linux/module.h> @@ -37,7 +38,6 @@ static int rt2x00lib_request_firmware(struct rt2x00_dev *rt2x00dev) char *fw_name; int retval; u16 crc; - u16 tmp; /* * Read correct firmware from harddisk. @@ -64,17 +64,37 @@ static int rt2x00lib_request_firmware(struct rt2x00_dev *rt2x00dev) } /* - * Validate the firmware using 16 bit CRC. - * The last 2 bytes of the firmware are the CRC - * so substract those 2 bytes from the CRC checksum, - * and set those 2 bytes to 0 when calculating CRC. + * Perform crc validation on the firmware. + * The last 2 bytes in the firmware array are the crc checksum itself, + * this means that we should never pass those 2 bytes to the crc + * algorithm. */ - tmp = 0; - crc = crc_itu_t(0, fw->data, fw->size - 2); - crc = crc_itu_t(crc, (u8 *)&tmp, 2); + if (test_bit(DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T, &rt2x00dev->flags)) { + /* + * Use the crc itu-t algorithm. + * Use 0 for the last 2 bytes to complete the checksum. + */ + crc = crc_itu_t(0, fw->data, fw->size - 2); + crc = crc_itu_t_byte(crc, 0); + crc = crc_itu_t_byte(crc, 0); + } else if (test_bit(DRIVER_REQUIRE_FIRMWARE_CCITT, &rt2x00dev->flags)) { + /* + * Use the crc ccitt algorithm. + * This will return the same value as the legacy driver which + * used bit ordering reversion on the both the firmware bytes + * before input input as well as on the final output. + * Obviously using crc ccitt directly is much more efficient. + */ + crc = crc_ccitt(~0, fw->data, fw->size - 2); + } else { + ERROR(rt2x00dev, "No checksum algorithm selected " + "for firmware validation.\n"); + retval = -ENOENT; + goto exit; + } if (crc != (fw->data[fw->size - 2] << 8 | fw->data[fw->size - 1])) { - ERROR(rt2x00dev, "Firmware CRC error.\n"); + ERROR(rt2x00dev, "Firmware checksum error.\n"); retval = -ENOENT; goto exit; } @@ -96,6 +116,9 @@ int rt2x00lib_load_firmware(struct rt2x00_dev *rt2x00dev) { int retval; + if (!test_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags)) + return 0; + if (!rt2x00dev->fw) { retval = rt2x00lib_request_firmware(rt2x00dev); if (retval) |