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>

diff --git a/drivers/net/wireless/rt2x00/Kconfig b/drivers/net/wireless/rt2x00/Kconfig
index da05b1f..28f3e5e 100644 (file)
--- a/drivers/net/wireless/rt2x00/Kconfig
+++ b/drivers/net/wireless/rt2x00/Kconfig
@@ -28,6 +28,7 @@ config RT2X00_LIB_USB
 config RT2X00_LIB_FIRMWARE
        boolean
        depends on RT2X00_LIB
+       select CRC_CCITT
        select CRC_ITU_T
        select FW_LOADER
 

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 7b67f96..6a25195 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -551,6 +551,8 @@ enum rt2x00_flags {
         * Driver features
         */
        DRIVER_REQUIRE_FIRMWARE,
+       DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T,
+       DRIVER_REQUIRE_FIRMWARE_CCITT,
        DRIVER_REQUIRE_BEACON_GUARD,
        DRIVER_REQUIRE_ATIM_QUEUE,
 

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 7620427..bc07c56 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -1017,11 +1017,9 @@ int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
         * If this is the first interface which is added,
         * we should load the firmware now.
         */
-       if (test_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags)) {
-               retval = rt2x00lib_load_firmware(rt2x00dev);
-               if (retval)
-                       return retval;
-       }
+       retval = rt2x00lib_load_firmware(rt2x00dev);
+       if (retval)
+               return retval;
 
        /*
         * Initialize the device.

diff --git a/drivers/net/wireless/rt2x00/rt2x00firmware.c b/drivers/net/wireless/rt2x00/rt2x00firmware.c
index 442ff80..4f9fe56 100644 (file)
--- 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)

diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 5e08541..b5ab771 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -2258,9 +2258,10 @@ static int rt61pci_probe_hw(struct rt2x00_dev *rt2x00dev)
        rt61pci_probe_hw_mode(rt2x00dev);
 
        /*
-        * This device requires firmware
+        * This device requires firmware.
         */
        __set_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags);
+       __set_bit(DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T, &rt2x00dev->flags);
 
        /*
         * Set the rssi offset.

diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 4e6466b..8ebf3fe 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -1849,9 +1849,10 @@ static int rt73usb_probe_hw(struct rt2x00_dev *rt2x00dev)
        rt73usb_probe_hw_mode(rt2x00dev);
 
        /*
-        * This device requires firmware
+        * This device requires firmware.
         */
        __set_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags);
+       __set_bit(DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T, &rt2x00dev->flags);
 
        /*
         * Set the rssi offset.