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Commit 64f222cc authored by Ulrich Kunitz's avatar Ulrich Kunitz Committed by David S. Miller
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[PATCH] zd1211rw: consistent handling of ZD1211 specific rates 



As pointed out by Daniel Drake, the zd1211rw driver used several
different rate values and names throughout the driver. He has
written a patch to change it and tweaked it after some pretty wild
ideas from my side. But the discussion helped me to understand the
problem better and I think I have nailed it down with this patch.

A zd-rate will consist from now on of a four-bit "pure" rate value
and a modulation type flag as used in the ZD1211 control set used
for packet transmission. This is consistent with the usage in the
zd_rates table. If possible these zd-rates should be used in the
code.

Signed-off-by: default avatarUlrich Kunitz <kune@deine-taler.de>
Signed-off-by: default avatarDaniel Drake <dsd@gentoo.org>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 8e97afe5

drivers/net/wireless/zd1211rw/zd_chip.c

+28 −23
Original line number Diff line number Diff line
@@ -1009,19 +1009,19 @@ int zd_chip_set_rts_cts_rate_locked(struct zd_chip *chip, 
	u32 value = 0;



	/* Modulation bit */

	if (ZD_CS_TYPE(rts_rate) == ZD_CS_OFDM)

	if (ZD_MODULATION_TYPE(rts_rate) == ZD_OFDM)

		rts_mod = ZD_RX_OFDM;



	dev_dbg_f(zd_chip_dev(chip), "rts_rate=%x preamble=%x\n",

		rts_rate, preamble);



	value |= rts_rate << RTSCTS_SH_RTS_RATE;

	value |= ZD_PURE_RATE(rts_rate) << RTSCTS_SH_RTS_RATE;

	value |= rts_mod << RTSCTS_SH_RTS_MOD_TYPE;

	value |= preamble << RTSCTS_SH_RTS_PMB_TYPE;

	value |= preamble << RTSCTS_SH_CTS_PMB_TYPE;



	/* We always send 11M self-CTS messages, like the vendor driver. */

	value |= ZD_CCK_RATE_11M << RTSCTS_SH_CTS_RATE;

	value |= ZD_PURE_RATE(ZD_CCK_RATE_11M) << RTSCTS_SH_CTS_RATE;

	value |= ZD_RX_CCK << RTSCTS_SH_CTS_MOD_TYPE;



	return zd_iowrite32_locked(chip, value, CR_RTS_CTS_RATE);
@@ -1328,7 +1328,7 @@ int zd_chip_set_basic_rates_locked(struct zd_chip *chip, u16 cr_rates) 
	return zd_iowrite32_locked(chip, cr_rates, CR_BASIC_RATE_TBL);

}



static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size)

static int ofdm_qual_db(u8 status_quality, u8 zd_rate, unsigned int size)

{

	static const u16 constants[] = {

		715, 655, 585, 540, 470, 410, 360, 315,
@@ -1342,7 +1342,7 @@ static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size) 
	/* It seems that their quality parameter is somehow per signal

	 * and is now transferred per bit.

	 */

	switch (rate) {

	switch (zd_rate) {

	case ZD_OFDM_RATE_6M:

	case ZD_OFDM_RATE_12M:

	case ZD_OFDM_RATE_24M:
@@ -1369,7 +1369,7 @@ static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size) 
			break;

	}



	switch (rate) {

	switch (zd_rate) {

	case ZD_OFDM_RATE_6M:

	case ZD_OFDM_RATE_9M:

		i += 3;
@@ -1393,11 +1393,11 @@ static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size) 
	return i;

}



static int ofdm_qual_percent(u8 status_quality, u8 rate, unsigned int size)

static int ofdm_qual_percent(u8 status_quality, u8 zd_rate, unsigned int size)

{

	int r;



	r = ofdm_qual_db(status_quality, rate, size);

	r = ofdm_qual_db(status_quality, zd_rate, size);

	ZD_ASSERT(r >= 0);

	if (r < 0)

		r = 0;
@@ -1458,12 +1458,17 @@ static int cck_qual_percent(u8 status_quality) 
	return r <= 100 ? r : 100;

}



static inline u8 zd_rate_from_ofdm_plcp_header(const void *rx_frame)

{

	return ZD_OFDM | zd_ofdm_plcp_header_rate(rx_frame);

}



u8 zd_rx_qual_percent(const void *rx_frame, unsigned int size,

	              const struct rx_status *status)

{

	return (status->frame_status&ZD_RX_OFDM) ?

		ofdm_qual_percent(status->signal_quality_ofdm,

			          zd_ofdm_plcp_header_rate(rx_frame),

					  zd_rate_from_ofdm_plcp_header(rx_frame),

			          size) :

		cck_qual_percent(status->signal_quality_cck);

}
@@ -1479,32 +1484,32 @@ u8 zd_rx_strength_percent(u8 rssi) 
u16 zd_rx_rate(const void *rx_frame, const struct rx_status *status)

{

	static const u16 ofdm_rates[] = {

		[ZD_OFDM_RATE_6M]  = 60,

		[ZD_OFDM_RATE_9M]  = 90,

		[ZD_OFDM_RATE_12M] = 120,

		[ZD_OFDM_RATE_18M] = 180,

		[ZD_OFDM_RATE_24M] = 240,

		[ZD_OFDM_RATE_36M] = 360,

		[ZD_OFDM_RATE_48M] = 480,

		[ZD_OFDM_RATE_54M] = 540,

		[ZD_OFDM_PLCP_RATE_6M]  = 60,

		[ZD_OFDM_PLCP_RATE_9M]  = 90,

		[ZD_OFDM_PLCP_RATE_12M] = 120,

		[ZD_OFDM_PLCP_RATE_18M] = 180,

		[ZD_OFDM_PLCP_RATE_24M] = 240,

		[ZD_OFDM_PLCP_RATE_36M] = 360,

		[ZD_OFDM_PLCP_RATE_48M] = 480,

		[ZD_OFDM_PLCP_RATE_54M] = 540,

	};

	u16 rate;

	if (status->frame_status & ZD_RX_OFDM) {

		/* Deals with PLCP OFDM rate (not zd_rates) */

		u8 ofdm_rate = zd_ofdm_plcp_header_rate(rx_frame);

		rate = ofdm_rates[ofdm_rate & 0xf];

	} else {

		u8 cck_rate = zd_cck_plcp_header_rate(rx_frame);

		switch (cck_rate) {

		case ZD_CCK_SIGNAL_1M:

		switch (zd_cck_plcp_header_signal(rx_frame)) {

		case ZD_CCK_PLCP_SIGNAL_1M:

			rate = 10;

			break;

		case ZD_CCK_SIGNAL_2M:

		case ZD_CCK_PLCP_SIGNAL_2M:

			rate = 20;

			break;

		case ZD_CCK_SIGNAL_5M5:

		case ZD_CCK_PLCP_SIGNAL_5M5:

			rate = 55;

			break;

		case ZD_CCK_SIGNAL_11M:

		case ZD_CCK_PLCP_SIGNAL_11M:

			rate = 110;

			break;

		default:

drivers/net/wireless/zd1211rw/zd_ieee80211.h

+27 −16
Original line number Diff line number Diff line
@@ -43,21 +43,25 @@ struct ofdm_plcp_header { 
	__le16 service;

} __attribute__((packed));



static inline u8 zd_ofdm_plcp_header_rate(

	const struct ofdm_plcp_header *header)

static inline u8 zd_ofdm_plcp_header_rate(const struct ofdm_plcp_header *header)

{

	return header->prefix[0] & 0xf;

}



/* These are referred to as zd_rates */

#define ZD_OFDM_RATE_6M		0xb

#define ZD_OFDM_RATE_9M		0xf

#define ZD_OFDM_RATE_12M	0xa

#define ZD_OFDM_RATE_18M	0xe

#define ZD_OFDM_RATE_24M	0x9

#define ZD_OFDM_RATE_36M	0xd

#define ZD_OFDM_RATE_48M	0x8

#define ZD_OFDM_RATE_54M	0xc

/* The following defines give the encoding of the 4-bit rate field in the

 * OFDM (802.11a/802.11g) PLCP header. Notify that these values are used to

 * define the zd-rate values for OFDM.

 *

 * See the struct zd_ctrlset definition in zd_mac.h.

 */

#define ZD_OFDM_PLCP_RATE_6M		0xb

#define ZD_OFDM_PLCP_RATE_9M		0xf

#define ZD_OFDM_PLCP_RATE_12M	0xa

#define ZD_OFDM_PLCP_RATE_18M	0xe

#define ZD_OFDM_PLCP_RATE_24M	0x9

#define ZD_OFDM_PLCP_RATE_36M	0xd

#define ZD_OFDM_PLCP_RATE_48M	0x8

#define ZD_OFDM_PLCP_RATE_54M	0xc



struct cck_plcp_header {

	u8 signal;
@@ -66,15 +70,22 @@ struct cck_plcp_header { 
	__le16 crc16;

} __attribute__((packed));



static inline u8 zd_cck_plcp_header_rate(const struct cck_plcp_header *header)

static inline u8 zd_cck_plcp_header_signal(const struct cck_plcp_header *header)

{

	return header->signal;

}



#define ZD_CCK_SIGNAL_1M	0x0a

#define ZD_CCK_SIGNAL_2M	0x14

#define ZD_CCK_SIGNAL_5M5	0x37

#define ZD_CCK_SIGNAL_11M	0x6e

/* These defines give the encodings of the signal field in the 802.11b PLCP

 * header. The signal field gives the bit rate of the following packet. Even

 * if technically wrong we use CCK here also for the 1 MBit/s and 2 MBit/s

 * rate to stay consistent with Zydas and our use of the term.

 *

 * Notify that these values are *not* used in the zd-rates.

 */

#define ZD_CCK_PLCP_SIGNAL_1M	0x0a

#define ZD_CCK_PLCP_SIGNAL_2M	0x14

#define ZD_CCK_PLCP_SIGNAL_5M5	0x37

#define ZD_CCK_PLCP_SIGNAL_11M	0x6e



enum ieee80211_std {

	IEEE80211B = 0x01,

drivers/net/wireless/zd1211rw/zd_mac.c

+27 −72
Original line number Diff line number Diff line
@@ -610,28 +610,6 @@ u8 zd_mac_get_channel(struct zd_mac *mac) 
	return channel;

}



/* If wrong rate is given, we are falling back to the slowest rate: 1MBit/s */

static u8 zd_rate_typed(u8 zd_rate)

{

	static const u8 typed_rates[16] = {

		[ZD_CCK_RATE_1M]	= ZD_CS_CCK|ZD_CCK_RATE_1M,

		[ZD_CCK_RATE_2M]	= ZD_CS_CCK|ZD_CCK_RATE_2M,

		[ZD_CCK_RATE_5_5M]	= ZD_CS_CCK|ZD_CCK_RATE_5_5M,

		[ZD_CCK_RATE_11M]	= ZD_CS_CCK|ZD_CCK_RATE_11M,

		[ZD_OFDM_RATE_6M]	= ZD_CS_OFDM|ZD_OFDM_RATE_6M,

		[ZD_OFDM_RATE_9M]	= ZD_CS_OFDM|ZD_OFDM_RATE_9M,

		[ZD_OFDM_RATE_12M]	= ZD_CS_OFDM|ZD_OFDM_RATE_12M,

		[ZD_OFDM_RATE_18M]	= ZD_CS_OFDM|ZD_OFDM_RATE_18M,

		[ZD_OFDM_RATE_24M]	= ZD_CS_OFDM|ZD_OFDM_RATE_24M,

		[ZD_OFDM_RATE_36M]	= ZD_CS_OFDM|ZD_OFDM_RATE_36M,

		[ZD_OFDM_RATE_48M]	= ZD_CS_OFDM|ZD_OFDM_RATE_48M,

		[ZD_OFDM_RATE_54M]	= ZD_CS_OFDM|ZD_OFDM_RATE_54M,

	};



	ZD_ASSERT(ZD_CS_RATE_MASK == 0x0f);

	return typed_rates[zd_rate & ZD_CS_RATE_MASK];

}



int zd_mac_set_mode(struct zd_mac *mac, u32 mode)

{

	struct ieee80211_device *ieee;
@@ -739,25 +717,30 @@ int zd_mac_get_range(struct zd_mac *mac, struct iw_range *range) 


static int zd_calc_tx_length_us(u8 *service, u8 zd_rate, u16 tx_length)

{

	/* ZD_PURE_RATE() must be used to remove the modulation type flag of

	 * the zd-rate values. */

	static const u8 rate_divisor[] = {

		[ZD_CCK_RATE_1M]	=  1,

		[ZD_CCK_RATE_2M]	=  2,

		[ZD_CCK_RATE_5_5M]	= 11, /* bits must be doubled */

		[ZD_CCK_RATE_11M]	= 11,

		[ZD_OFDM_RATE_6M]	=  6,

		[ZD_OFDM_RATE_9M]	=  9,

		[ZD_OFDM_RATE_12M]	= 12,

		[ZD_OFDM_RATE_18M]	= 18,

		[ZD_OFDM_RATE_24M]	= 24,

		[ZD_OFDM_RATE_36M]	= 36,

		[ZD_OFDM_RATE_48M]	= 48,

		[ZD_OFDM_RATE_54M]	= 54,

		[ZD_PURE_RATE(ZD_CCK_RATE_1M)]		=  1,

		[ZD_PURE_RATE(ZD_CCK_RATE_2M)]		=  2,



		/* bits must be doubled */

		[ZD_PURE_RATE(ZD_CCK_RATE_5_5M)]	= 11,



		[ZD_PURE_RATE(ZD_CCK_RATE_11M)]		= 11,

		[ZD_PURE_RATE(ZD_OFDM_RATE_6M)]		=  6,

		[ZD_PURE_RATE(ZD_OFDM_RATE_9M)]		=  9,

		[ZD_PURE_RATE(ZD_OFDM_RATE_12M)]	= 12,

		[ZD_PURE_RATE(ZD_OFDM_RATE_18M)]	= 18,

		[ZD_PURE_RATE(ZD_OFDM_RATE_24M)]	= 24,

		[ZD_PURE_RATE(ZD_OFDM_RATE_36M)]	= 36,

		[ZD_PURE_RATE(ZD_OFDM_RATE_48M)]	= 48,

		[ZD_PURE_RATE(ZD_OFDM_RATE_54M)]	= 54,

	};



	u32 bits = (u32)tx_length * 8;

	u32 divisor;



	divisor = rate_divisor[zd_rate];

	divisor = rate_divisor[ZD_PURE_RATE(zd_rate)];

	if (divisor == 0)

		return -EINVAL;
@@ -780,52 +763,24 @@ static int zd_calc_tx_length_us(u8 *service, u8 zd_rate, u16 tx_length) 
	return bits/divisor;

}



enum {

	R2M_SHORT_PREAMBLE = 0x01,

	R2M_11A		   = 0x02,

};



static u8 zd_rate_to_modulation(u8 zd_rate, int flags)

{

	u8 modulation;



	modulation = zd_rate_typed(zd_rate);

	if (flags & R2M_SHORT_PREAMBLE) {

		switch (ZD_CS_RATE(modulation)) {

		case ZD_CCK_RATE_2M:

		case ZD_CCK_RATE_5_5M:

		case ZD_CCK_RATE_11M:

			modulation |= ZD_CS_CCK_PREA_SHORT;

			return modulation;

		}

	}

	if (flags & R2M_11A) {

		if (ZD_CS_TYPE(modulation) == ZD_CS_OFDM)

			modulation |= ZD_CS_OFDM_MODE_11A;

	}

	return modulation;

}



static void cs_set_modulation(struct zd_mac *mac, struct zd_ctrlset *cs,

	                      struct ieee80211_hdr_4addr *hdr)

{

	struct ieee80211softmac_device *softmac = ieee80211_priv(mac->netdev);

	u16 ftype = WLAN_FC_GET_TYPE(le16_to_cpu(hdr->frame_ctl));

	u8 rate, zd_rate;

	u8 rate;

	int is_mgt = (ftype == IEEE80211_FTYPE_MGMT) != 0;

	int is_multicast = is_multicast_ether_addr(hdr->addr1);

	int short_preamble = ieee80211softmac_short_preamble_ok(softmac,

		is_multicast, is_mgt);

	int flags = 0;



	/* FIXME: 802.11a? */

	rate = ieee80211softmac_suggest_txrate(softmac, is_multicast, is_mgt);

	cs->modulation = rate_to_zd_rate(rate);



	if (short_preamble)

		flags |= R2M_SHORT_PREAMBLE;



	zd_rate = rate_to_zd_rate(rate);

	cs->modulation = zd_rate_to_modulation(zd_rate, flags);

	/* Set short preamble bit when appropriate */

	if (short_preamble && ZD_MODULATION_TYPE(cs->modulation) == ZD_CCK

	    && cs->modulation != ZD_CCK_RATE_1M)

		cs->modulation |= ZD_CCK_PREA_SHORT;

}



static void cs_set_control(struct zd_mac *mac, struct zd_ctrlset *cs,
@@ -864,7 +819,7 @@ static void cs_set_control(struct zd_mac *mac, struct zd_ctrlset *cs, 
		cs->control |= ZD_CS_RTS;



	/* Use CTS-to-self protection if required */

	if (ZD_CS_TYPE(cs->modulation) == ZD_CS_OFDM &&

	if (ZD_MODULATION_TYPE(cs->modulation) == ZD_OFDM &&

			ieee80211softmac_protection_needed(softmac)) {

		/* FIXME: avoid sending RTS *and* self-CTS, is that correct? */

		cs->control &= ~ZD_CS_RTS;
@@ -925,7 +880,7 @@ static int fill_ctrlset(struct zd_mac *mac, 
	 * - see line 53 of zdinlinef.h

	 */

	cs->service = 0;

	r = zd_calc_tx_length_us(&cs->service, ZD_CS_RATE(cs->modulation),

	r = zd_calc_tx_length_us(&cs->service, ZD_RATE(cs->modulation),

		                 le16_to_cpu(cs->tx_length));

	if (r < 0)

		return r;
@@ -934,7 +889,7 @@ static int fill_ctrlset(struct zd_mac *mac, 
	if (next_frag_len == 0) {

		cs->next_frame_length = 0;

	} else {

		r = zd_calc_tx_length_us(NULL, ZD_CS_RATE(cs->modulation),

		r = zd_calc_tx_length_us(NULL, ZD_RATE(cs->modulation),

			                 next_frag_len);

		if (r < 0)

			return r;

drivers/net/wireless/zd1211rw/zd_mac.h

+44 −21
Original line number Diff line number Diff line
@@ -40,28 +40,51 @@ struct zd_ctrlset { 


#define ZD_CS_RESERVED_SIZE	25



/* zd_crtlset field modulation */

#define ZD_CS_RATE_MASK		0x0f

#define ZD_CS_TYPE_MASK		0x10

#define ZD_CS_RATE(modulation) ((modulation) & ZD_CS_RATE_MASK)

#define ZD_CS_TYPE(modulation) ((modulation) & ZD_CS_TYPE_MASK)



#define ZD_CS_CCK		0x00

#define ZD_CS_OFDM		0x10



/* These are referred to as zd_rates */

#define ZD_CCK_RATE_1M	0x00

#define ZD_CCK_RATE_2M	0x01

#define ZD_CCK_RATE_5_5M	0x02

#define ZD_CCK_RATE_11M	0x03

/* The rates for OFDM are encoded as in the PLCP header. Use ZD_OFDM_RATE_*.

/* The field modulation of struct zd_ctrlset controls the bit rate, the use

 * of short or long preambles in 802.11b (CCK mode) or the use of 802.11a or

 * 802.11g in OFDM mode.

 *

 * The term zd-rate is used for the combination of the modulation type flag

 * and the "pure" rate value.

 */

#define ZD_PURE_RATE_MASK       0x0f

#define ZD_MODULATION_TYPE_MASK 0x10

#define ZD_RATE_MASK            (ZD_PURE_RATE_MASK|ZD_MODULATION_TYPE_MASK)

#define ZD_PURE_RATE(modulation) ((modulation) & ZD_PURE_RATE_MASK)

#define ZD_MODULATION_TYPE(modulation) ((modulation) & ZD_MODULATION_TYPE_MASK)

#define ZD_RATE(modulation) ((modulation) & ZD_RATE_MASK)



/* The two possible modulation types. Notify that 802.11b doesn't use the CCK

 * codeing for the 1 and 2 MBit/s rate. We stay with the term here to remain

 * consistent with uses the term at other places.

  */

#define ZD_CCK                  0x00

#define ZD_OFDM                 0x10



/* bit 5 is preamble (when in CCK mode), or a/g selection (when in OFDM mode) */

#define ZD_CS_CCK_PREA_LONG	0x00

#define ZD_CS_CCK_PREA_SHORT	0x20

#define ZD_CS_OFDM_MODE_11G	0x00

#define ZD_CS_OFDM_MODE_11A	0x20

/* The ZD1211 firmware uses proprietary encodings of the 802.11b (CCK) rates.

 * For OFDM the PLCP rate encodings are used. We combine these "pure" rates

 * with the modulation type flag and call the resulting values zd-rates.

 */

#define ZD_CCK_RATE_1M          (ZD_CCK|0x00)

#define ZD_CCK_RATE_2M          (ZD_CCK|0x01)

#define ZD_CCK_RATE_5_5M        (ZD_CCK|0x02)

#define ZD_CCK_RATE_11M         (ZD_CCK|0x03)

#define ZD_OFDM_RATE_6M         (ZD_OFDM|ZD_OFDM_PLCP_RATE_6M)

#define ZD_OFDM_RATE_9M         (ZD_OFDM|ZD_OFDM_PLCP_RATE_9M)

#define ZD_OFDM_RATE_12M        (ZD_OFDM|ZD_OFDM_PLCP_RATE_12M)

#define ZD_OFDM_RATE_18M        (ZD_OFDM|ZD_OFDM_PLCP_RATE_18M)

#define ZD_OFDM_RATE_24M        (ZD_OFDM|ZD_OFDM_PLCP_RATE_24M)

#define ZD_OFDM_RATE_36M        (ZD_OFDM|ZD_OFDM_PLCP_RATE_36M)

#define ZD_OFDM_RATE_48M        (ZD_OFDM|ZD_OFDM_PLCP_RATE_48M)

#define ZD_OFDM_RATE_54M        (ZD_OFDM|ZD_OFDM_PLCP_RATE_54M)



/* The bit 5 of the zd_ctrlset modulation field controls the preamble in CCK

 * mode or the 802.11a/802.11g selection in OFDM mode.

 */

#define ZD_CCK_PREA_LONG        0x00

#define ZD_CCK_PREA_SHORT       0x20

#define ZD_OFDM_MODE_11G        0x00

#define ZD_OFDM_MODE_11A        0x20



/* zd_ctrlset control field */

#define ZD_CS_NEED_RANDOM_BACKOFF	0x01