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rt2x00: Re-order tx descriptor writing code in drivers.
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Where possible, write the tx descriptor words from start to end, to
follow a logical ordering of words.
Where this is not possible (in rt2400pci, rt2500pci and rt61pci) add
a comment as to why word 0 needs to be written last.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Gertjan van Wingerde authored and John W. Linville committed May 12, 2010
1 parent 6b97cb0 commit e01f1ec
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Showing 5 changed files with 59 additions and 44 deletions.
5 changes: 5 additions & 0 deletions drivers/net/wireless/rt2x00/rt2400pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1039,6 +1039,11 @@ static void rt2400pci_write_tx_desc(struct rt2x00_dev *rt2x00dev,
rt2x00_set_field32(&word, TXD_W3_PLCP_LENGTH_HIGH_BUSY, 1);
rt2x00_desc_write(txd, 4, word);

/*
* Writing TXD word 0 must the last to prevent a race condition with
* the device, whereby the device may take hold of the TXD before we
* finished updating it.
*/
rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_OWNER_NIC, 1);
rt2x00_set_field32(&word, TXD_W0_VALID, 1);
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5 changes: 5 additions & 0 deletions drivers/net/wireless/rt2x00/rt2500pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1193,6 +1193,11 @@ static void rt2500pci_write_tx_desc(struct rt2x00_dev *rt2x00dev,
test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags));
rt2x00_desc_write(txd, 10, word);

/*
* Writing TXD word 0 must the last to prevent a race condition with
* the device, whereby the device may take hold of the TXD before we
* finished updating it.
*/
rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_OWNER_NIC, 1);
rt2x00_set_field32(&word, TXD_W0_VALID, 1);
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36 changes: 18 additions & 18 deletions drivers/net/wireless/rt2x00/rt2500usb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1039,6 +1039,24 @@ static void rt2500usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
/*
* Start writing the descriptor words.
*/
rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_RETRY_LIMIT, txdesc->retry_limit);
rt2x00_set_field32(&word, TXD_W0_MORE_FRAG,
test_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_ACK,
test_bit(ENTRY_TXD_ACK, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_TIMESTAMP,
test_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_OFDM,
(txdesc->rate_mode == RATE_MODE_OFDM));
rt2x00_set_field32(&word, TXD_W0_NEW_SEQ,
test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_IFS, txdesc->ifs);
rt2x00_set_field32(&word, TXD_W0_DATABYTE_COUNT, txdesc->length);
rt2x00_set_field32(&word, TXD_W0_CIPHER, !!txdesc->cipher);
rt2x00_set_field32(&word, TXD_W0_KEY_ID, txdesc->key_idx);
rt2x00_desc_write(txd, 0, word);

rt2x00_desc_read(txd, 1, &word);
rt2x00_set_field32(&word, TXD_W1_IV_OFFSET, txdesc->iv_offset);
rt2x00_set_field32(&word, TXD_W1_AIFS, txdesc->aifs);
Expand All @@ -1057,24 +1075,6 @@ static void rt2500usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
_rt2x00_desc_write(txd, 3, skbdesc->iv[0]);
_rt2x00_desc_write(txd, 4, skbdesc->iv[1]);
}

rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_RETRY_LIMIT, txdesc->retry_limit);
rt2x00_set_field32(&word, TXD_W0_MORE_FRAG,
test_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_ACK,
test_bit(ENTRY_TXD_ACK, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_TIMESTAMP,
test_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_OFDM,
(txdesc->rate_mode == RATE_MODE_OFDM));
rt2x00_set_field32(&word, TXD_W0_NEW_SEQ,
test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_IFS, txdesc->ifs);
rt2x00_set_field32(&word, TXD_W0_DATABYTE_COUNT, txdesc->length);
rt2x00_set_field32(&word, TXD_W0_CIPHER, !!txdesc->cipher);
rt2x00_set_field32(&word, TXD_W0_KEY_ID, txdesc->key_idx);
rt2x00_desc_write(txd, 0, word);
}

/*
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5 changes: 5 additions & 0 deletions drivers/net/wireless/rt2x00/rt61pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1813,6 +1813,11 @@ static void rt61pci_write_tx_desc(struct rt2x00_dev *rt2x00dev,
rt2x00_desc_write(txd, 11, word);
}

/*
* Writing TXD word 0 must the last to prevent a race condition with
* the device, whereby the device may take hold of the TXD before we
* finished updating it.
*/
rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_OWNER_NIC, 1);
rt2x00_set_field32(&word, TXD_W0_VALID, 1);
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52 changes: 26 additions & 26 deletions drivers/net/wireless/rt2x00/rt73usb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1446,6 +1446,32 @@ static void rt73usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
/*
* Start writing the descriptor words.
*/
rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_BURST,
test_bit(ENTRY_TXD_BURST, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_VALID, 1);
rt2x00_set_field32(&word, TXD_W0_MORE_FRAG,
test_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_ACK,
test_bit(ENTRY_TXD_ACK, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_TIMESTAMP,
test_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_OFDM,
(txdesc->rate_mode == RATE_MODE_OFDM));
rt2x00_set_field32(&word, TXD_W0_IFS, txdesc->ifs);
rt2x00_set_field32(&word, TXD_W0_RETRY_MODE,
test_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_TKIP_MIC,
test_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_KEY_TABLE,
test_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_KEY_INDEX, txdesc->key_idx);
rt2x00_set_field32(&word, TXD_W0_DATABYTE_COUNT, txdesc->length);
rt2x00_set_field32(&word, TXD_W0_BURST2,
test_bit(ENTRY_TXD_BURST, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_CIPHER_ALG, txdesc->cipher);
rt2x00_desc_write(txd, 0, word);

rt2x00_desc_read(txd, 1, &word);
rt2x00_set_field32(&word, TXD_W1_HOST_Q_ID, txdesc->queue);
rt2x00_set_field32(&word, TXD_W1_AIFSN, txdesc->aifs);
Expand Down Expand Up @@ -1473,32 +1499,6 @@ static void rt73usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
TXPOWER_TO_DEV(rt2x00dev->tx_power));
rt2x00_set_field32(&word, TXD_W5_WAITING_DMA_DONE_INT, 1);
rt2x00_desc_write(txd, 5, word);

rt2x00_desc_read(txd, 0, &word);
rt2x00_set_field32(&word, TXD_W0_BURST,
test_bit(ENTRY_TXD_BURST, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_VALID, 1);
rt2x00_set_field32(&word, TXD_W0_MORE_FRAG,
test_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_ACK,
test_bit(ENTRY_TXD_ACK, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_TIMESTAMP,
test_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_OFDM,
(txdesc->rate_mode == RATE_MODE_OFDM));
rt2x00_set_field32(&word, TXD_W0_IFS, txdesc->ifs);
rt2x00_set_field32(&word, TXD_W0_RETRY_MODE,
test_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_TKIP_MIC,
test_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_KEY_TABLE,
test_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_KEY_INDEX, txdesc->key_idx);
rt2x00_set_field32(&word, TXD_W0_DATABYTE_COUNT, txdesc->length);
rt2x00_set_field32(&word, TXD_W0_BURST2,
test_bit(ENTRY_TXD_BURST, &txdesc->flags));
rt2x00_set_field32(&word, TXD_W0_CIPHER_ALG, txdesc->cipher);
rt2x00_desc_write(txd, 0, word);
}

/*
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