rt2x00: Hardcode TX ack timeout and consume time
The calculated values for the ACK timeout and ACK
consume time are different then the values as
used by the Legacy drivers.
After testing from James Ledwith it appeared that
the calculated values caused a high amount of TX
failures, and the values from the Legacy drivers
were the most optimal to prevent TX failure due to
excessive retries.
The symptoms of this problem:
- Rate control module always falls back to 1Mbs
- Low throughput when bitrate was fixed
Possible side-effects (not confirmed but highly likely)
- Problems with DHCP
- Broken connections due to lack of probe response
This should fix at least:
Kernel bugzilla reports: [13362], [13009], [9273]
Fedora bugzilla reports: [443203]
but possible some additional bugs as well.
Signed-off-by: Ivo van Doorn <[email protected]>
---
John, this patch has not yet been confirmed by any of the above bugzilla reports,
but I do think this should be merged as soon as possible to 2.6.31 since this issue
has been marked as regression for quite some time now. :)
Thanks.
---
diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index 164df93..798f625 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -331,9 +331,8 @@ static void rt2400pci_config_erp(struct rt2x00_dev *rt2x00dev,
preamble_mask = erp->short_preamble << 3;
rt2x00pci_register_read(rt2x00dev, TXCSR1, ®);
- rt2x00_set_field32(®, TXCSR1_ACK_TIMEOUT, erp->ack_timeout);
- rt2x00_set_field32(®, TXCSR1_ACK_CONSUME_TIME,
- erp->ack_consume_time);
+ rt2x00_set_field32(®, TXCSR1_ACK_TIMEOUT, 0x1ff);
+ rt2x00_set_field32(®, TXCSR1_ACK_CONSUME_TIME, 0x13a);
rt2x00_set_field32(®, TXCSR1_TSF_OFFSET, IEEE80211_HEADER);
rt2x00_set_field32(®, TXCSR1_AUTORESPONDER, 1);
rt2x00pci_register_write(rt2x00dev, TXCSR1, reg);
diff --git a/drivers/net/wireless/rt2x00/rt2500pci.c b/drivers/net/wireless/rt2x00/rt2500pci.c
index 4186582..2e872ac 100644
--- a/drivers/net/wireless/rt2x00/rt2500pci.c
+++ b/drivers/net/wireless/rt2x00/rt2500pci.c
@@ -337,9 +337,8 @@ static void rt2500pci_config_erp(struct rt2x00_dev *rt2x00dev,
preamble_mask = erp->short_preamble << 3;
rt2x00pci_register_read(rt2x00dev, TXCSR1, ®);
- rt2x00_set_field32(®, TXCSR1_ACK_TIMEOUT, erp->ack_timeout);
- rt2x00_set_field32(®, TXCSR1_ACK_CONSUME_TIME,
- erp->ack_consume_time);
+ rt2x00_set_field32(®, TXCSR1_ACK_TIMEOUT, 0x162);
+ rt2x00_set_field32(®, TXCSR1_ACK_CONSUME_TIME, 0xa2);
rt2x00_set_field32(®, TXCSR1_TSF_OFFSET, IEEE80211_HEADER);
rt2x00_set_field32(®, TXCSR1_AUTORESPONDER, 1);
rt2x00pci_register_write(rt2x00dev, TXCSR1, reg);
diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index b04f59b..22dd6d9 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -488,10 +488,6 @@ static void rt2500usb_config_erp(struct rt2x00_dev *rt2x00dev,
{
u16 reg;
- rt2500usb_register_read(rt2x00dev, TXRX_CSR1, ®);
- rt2x00_set_field16(®, TXRX_CSR1_ACK_TIMEOUT, erp->ack_timeout);
- rt2500usb_register_write(rt2x00dev, TXRX_CSR1, reg);
-
rt2500usb_register_read(rt2x00dev, TXRX_CSR10, ®);
rt2x00_set_field16(®, TXRX_CSR10_AUTORESPOND_PREAMBLE,
!!erp->short_preamble);
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index 1307873..9fe770f 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -580,8 +580,7 @@ static void rt2800usb_config_erp(struct rt2x00_dev *rt2x00dev,
u32 reg;
rt2x00usb_register_read(rt2x00dev, TX_TIMEOUT_CFG, ®);
- rt2x00_set_field32(®, TX_TIMEOUT_CFG_RX_ACK_TIMEOUT,
- DIV_ROUND_UP(erp->ack_timeout, erp->slot_time));
+ rt2x00_set_field32(®, TX_TIMEOUT_CFG_RX_ACK_TIMEOUT, 0x20);
rt2x00usb_register_write(rt2x00dev, TX_TIMEOUT_CFG, reg);
rt2x00usb_register_read(rt2x00dev, AUTO_RSP_CFG, ®);
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 7bede90..196de8a 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -424,9 +424,6 @@ struct rt2x00lib_erp {
int short_preamble;
int cts_protection;
- int ack_timeout;
- int ack_consume_time;
-
u32 basic_rates;
int slot_time;
diff --git a/drivers/net/wireless/rt2x00/rt2x00config.c b/drivers/net/wireless/rt2x00/rt2x00config.c
index 3501788..40a201e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00config.c
+++ b/drivers/net/wireless/rt2x00/rt2x00config.c
@@ -94,17 +94,6 @@ void rt2x00lib_config_erp(struct rt2x00_dev *rt2x00dev,
erp.difs = bss_conf->use_short_slot ? SHORT_DIFS : DIFS;
erp.eifs = bss_conf->use_short_slot ? SHORT_EIFS : EIFS;
- erp.ack_timeout = PLCP + erp.difs + GET_DURATION(ACK_SIZE, 10);
- erp.ack_consume_time = SIFS + PLCP + GET_DURATION(ACK_SIZE, 10);
-
- if (bss_conf->use_short_preamble) {
- erp.ack_timeout += SHORT_PREAMBLE;
- erp.ack_consume_time += SHORT_PREAMBLE;
- } else {
- erp.ack_timeout += PREAMBLE;
- erp.ack_consume_time += PREAMBLE;
- }
-
erp.basic_rates = bss_conf->basic_rates;
erp.beacon_int = bss_conf->beacon_int;
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index f4b4b86..b20e3ea 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -598,7 +598,7 @@ static void rt61pci_config_erp(struct rt2x00_dev *rt2x00dev,
u32 reg;
rt2x00pci_register_read(rt2x00dev, TXRX_CSR0, ®);
- rt2x00_set_field32(®, TXRX_CSR0_RX_ACK_TIMEOUT, erp->ack_timeout);
+ rt2x00_set_field32(®, TXRX_CSR0_RX_ACK_TIMEOUT, 0x32);
rt2x00_set_field32(®, TXRX_CSR0_TSF_OFFSET, IEEE80211_HEADER);
rt2x00pci_register_write(rt2x00dev, TXRX_CSR0, reg);
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 90e1172..1cbd9b4 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -561,7 +561,7 @@ static void rt73usb_config_erp(struct rt2x00_dev *rt2x00dev,
u32 reg;
rt2x00usb_register_read(rt2x00dev, TXRX_CSR0, ®);
- rt2x00_set_field32(®, TXRX_CSR0_RX_ACK_TIMEOUT, erp->ack_timeout);
+ rt2x00_set_field32(®, TXRX_CSR0_RX_ACK_TIMEOUT, 0x32);
rt2x00_set_field32(®, TXRX_CSR0_TSF_OFFSET, IEEE80211_HEADER);
rt2x00usb_register_write(rt2x00dev, TXRX_CSR0, reg);
On Tuesday 08 September 2009, John W. Linville wrote:
> On Sun, Sep 06, 2009 at 03:14:23PM +0200, Ivo van Doorn wrote:
> > rt2x00: Hardcode TX ack timeout and consume time
>
> > John, this patch has not yet been confirmed by any of the above bugzilla reports,
> > but I do think this should be merged as soon as possible to 2.6.31 since this issue
> > has been marked as regression for quite some time now. :)
>
> Well, given how late it is in the 2.6.31 cycle and the fact that this
> problem has persisted for a while I think I'll just let this slip to
> 2.6.32 -- good enough?
Well preferably not, but I can sit it out and try to push it into -stable
for 2.6.31.1. That might be the easiest solution which worked the last time
when I had an urgent fix late in the release cycle as well. :)
Ivo
On Tue, Sep 08, 2009 at 02:06:09PM +0200, Richard Zidlicky wrote:
>
> it does significantly improve rt73usb performance and stability of ping times.
further data.. downloads improve significantly but uploads still require manual rate
setting else they fall back to 1MBit immediately.
Richard
On Sun, Sep 06, 2009 at 03:14:23PM +0200, Ivo van Doorn wrote:
> rt2x00: Hardcode TX ack timeout and consume time
Hi,
it does significantly improve rt73usb performance and stability of ping times.
I can still get almost the double performance and much better ping times when
setting the rate manually.
> John, this patch has not yet been confirmed by any of the above bugzilla reports,
> but I do think this should be merged as soon as possible to 2.6.31 since this issue
> has been marked as regression for quite some time now. :)
imho it should be merged even if it does not fully fix every imaginable problem.
Actually I would wish critical fixes would be merged much more aggressively,
eg rt73usb was critically broken before Pavel Roskin' recent off-by-1 register
access fix - causing all kinds of weird problems probably including filesystem
damage.
Seems some other fixes are also critical - it would be nice to have all important
fixes in eg in 2.6.30.6 (if it ever comes) as it is not quite trivial to cherrypick
them from the list when the code diverges too much from mainline.
Richard
On Sun, Sep 06, 2009 at 03:14:23PM +0200, Ivo van Doorn wrote:
> rt2x00: Hardcode TX ack timeout and consume time
> John, this patch has not yet been confirmed by any of the above bugzilla reports,
> but I do think this should be merged as soon as possible to 2.6.31 since this issue
> has been marked as regression for quite some time now. :)
Well, given how late it is in the 2.6.31 cycle and the fact that this
problem has persisted for a while I think I'll just let this slip to
2.6.32 -- good enough?
John
--
John W. Linville Someday the world will need a hero, and you
[email protected] might be all we have. Be ready.