commit 8bfae4f9 upstream.

Sometimes while CPU have some load and ath5k doing the wireless
interface reset the whole WiSoC completely freezes. Set of tests shows
that using atomic delay function while we wait interface reset helps to
avoid such freezes.

The easiest way to reproduce this issue: create a station interface,
start continous scan with wpa_supplicant and load CPU by something. Or
just create multiple station interfaces and put them all in continous
scan.

This patch partially reverts the commit 1846ac3d ("ath5k: Use
usleep_range where possible"), which replaces initial udelay()
by usleep_range().

I do not know actual source of this issue, but all looks like that HW
freeze is caused by transaction on internal SoC bus, while wireless
block is in reset state.

Also I should note that I do not know how many chips are affected, but I
did not see this issue with chips, other than AR5312.

CC: Jiri Slaby <jirislaby@gmail.com>
CC: Nick Kossifidis <mickflemm@gmail.com>
CC: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Fixes: 1846ac3d ("ath5k: Use usleep_range where possible")
Reported-by: Christophe Prevotaux <c.prevotaux@rural-networks.com>
Tested-by: Christophe Prevotaux <c.prevotaux@rural-networks.com>
Tested-by: Eric Bree <ebree@nltinc.com>
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

Stop returning negative values from ath5k_eeprom_mode_from_channel.
Yell loudly about that case in that function instead and return the
default/zero/mode A. This cleans up the callers, but needs to pass ah
down to ath5k_eeprom_mode_from_channel for ATH5K_WARN. For that
purpose we also need the declaration to be moved to ath5k.h.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

It can, if invalid argument given, return a negative value. In that
case we would access arrays out-of-bounds and such. Check the value
and yell loudly if that happened as it would be a bug in the
implementation. (Instead of silently corrupting memory.)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Nick Kossifidis <mickflemm@gmail.com>
Cc: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

'|' has higher precedence than ?:.  Since AR5K_PHY_TURBO_MODE is 0x1 and
"AR5K_PHY_TURBO_MODE | (ah->ah_radio == AR5K_RF2425)" is true then we
always set turbo to zero.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Use a more current logging style.
Make sure all output is prefixed appropriately.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

By swithing from our __raw_read and __raw_write functions to ioread32 and iowrite32,
benchmarks on my desk with iperf went from 11MBps to 18.1MBps using the AHB bus
on an EnGenius ECB3500 running OpenWRT.
Signed-off-by: Jonathan Bither <jonbither@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

DaveM said:
   Please, this kind of stuff rots forever and not using bool properly
   drives me crazy.

Joe Perches <joe@perches.com> gave me the spatch script:

	@@
	bool b;
	@@
	-b = 0
	+b = false
	@@
	bool b;
	@@
	-b = 1
	+b = true

I merely installed coccinelle, read the documentation and took credit.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

No functional changes

Add kernel doc for all ath5k_hw_* functions and strcucts. Also do some cleanup,
rename ath5k_hw_init_beacon to ath5k_hw_init_beacon_timers, remove an unused
variable from ath5k_hw_pcu_init and a few obsolete macros, mostly related to XR.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Use usleep_range where possible to reduce busy waits
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Remove unnecessary includes from base.h.  Add includes to other files as
necessary.  Don't include base.h unless needed.

Move declarations for functions in base.c from ath5k.h to base.h.

Use a better named define to protect base.h against double inclusion.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

When checking for the band, use channel->band.

Change ath5k_hw_nic_wakeup() and ath5k_channel_ok() to take
ieee80211_channel.  Change ath5k_hw_radio_revision() to take
ieee80211_band.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

XR is a proprietary feature of the chipset.  It's not supported and
should not be supported.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Both ath5k_hw and ath5k_softc represent one instance of the hardware.
This duplication is historical and is not needed anymore.

Keep the name "ath5k_hw" for the merged structure and "ah" for the
variable pointing to it.  "ath5k_hw" is shorter than "ath5k_softc", more
descriptive and more widely used.

Put the combined structure to ath5k.h where the old ath5k_softc used to
be. Move some code from base.h to ath5k.h as needed.

Remove memory allocation for struct ath5k_hw and the corresponding error
handling.  Merge iobase and ah_iobase fields.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

While 32 KHz sleep clock might provide some power saving benefits,
it is also a major source of stability issues, on OpenWrt it produced
some reproducible data bus errors on register accesses on several
different MIPS platforms.

All the Atheros drivers that I can find do not enable this feature,
so it makes sense to leave it disabled in ath5k as well.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

enabling the sleep clock alters the AR5K_USEC_32 field, but disabling
it didn't restore it.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Signed-off-by: Pavel Roskin <proski@gnu.org>

The reg variable is only used by __raw_writel() and __raw_readl(), which
should guarantee memory access in the right order.
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Disable fast channel change by default on AR2413/AR5413 due to
some bug reports (it still works for me but it's better to be safe).
Add a module parameter "fastchanswitch" in case anyone wants to enable
it and play with it.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

  CC [M]  drivers/net/wireless/ath/ath5k/reset.o
drivers/net/wireless/ath/ath5k/reset.c: In function ‘ath5k_hw_init_core_clock’:
drivers/net/wireless/ath/ath5k/reset.c:100:51: warning: ‘txf2txs’ may be used uninitialized in this function
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Introduce a helper function to get the EEPROM mode from channel and remove
multiple similar switch statements. Also since it's now easy to get the EEPROM
mode from the channel, use them inside the functions which need it, instead of
passing a redundant ee_mode parameter.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Remove redundant defines.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Use function pci_is_pcie() instead of accessing struct member directly.

CC: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

On WiSoc we cannot access mac register before it is resetted.
It will crash hardware otherwise.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

To be able to support other busses than PCI check if pci device
structure is initialized.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Clean up CHANNEL_T(URBO), use AR5K_BWMODE_40MHZ instead
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Since we set antenna flags on phy init and ack bitrate
 mode on pcu init, there is no need to save/restore sta_id
 flags on ath5k_hw_reset. Also we don't need to re-set our
 mac address because it's not affected by resets.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Add synth-only channel change for AR2413/5413. When we call
 ath5k_reset with a channel ath5k_hw_reset will first try to
 set channel on PHY while PHY is running instead of doing a normal
 full reset. To do this phy_init has to change to implement this
 functionality.

 * Clean up change_channel flag, what it really did was skip PCU
 registers when setting initvals. This is done because on reset
 PCU registers are not affected (except the registers we set
 in pcu init and -due to hw problems- TSF). Use a new skip_pcu
 flag that's not misleading instead. In the future we might use
 that to also skip PCU reset and save us the TSF etc problems
 (needs testing because standard practice is to reset everything).

 * Use fast channel change only when setting channel, and set skip_pcu
 to false only on init. When we reset the card due to DMA or PHY
 problems skip pcu but never do a fast channel change.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Set correct PLL settings for each bwmode
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * On turbo mode increase PHY settling times, note that
 we only increase switch settling time on AR5212 as indicated
 by initvals.

 * A few cleanups: Move frame control settings for AR5210 from
 reset_tx_queue to tweak_initvals and remove phy_scal settings
 from tweak_initvals (we tweak them alread on set_sleep_clock).
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Now that we properly set rx/tx latencies for AR5311 remove
 that old buggy part of code left inside ath5k_hw_tweak_initval_settings
 that was never executed (you can't have an RF5112 radio on a mac older
 than AR5212). Also use a magic value for 5311 PHY_SCAL value.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Handle all usec parameters in one function. It's much cleaner
 this way.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Stop PCU receive logic (DRU) durring reset
 We need to be sure pcu is not active when trying to stop rx dma
 right now this is done on ath5k_reset (base.c) but later we are
 going to clean it up.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * Add a new function to stop rx/tx dma and use in when reset starts
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

 * No functional changes

 * Clean up reset:
 Introduce init functions for each unit and call them instead
 of having everything inside ath5k_hw_reset (it's just c/p for
 now so nothing changes except calling order -I tested it with
 various cards and it's ok-)

 * Further cleanups:
 ofdm_timings belongs to phy.c
 rate_duration belongs to pcu.c
 clock functions are general and belong to reset.c (more to follow)

 * Reorder functions for better organization:
 We start with helpers and other functions follow in categories,
 init functions are last
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Support up to 4 virtual APs and as many virtual STA interfaces
as desired.

This patch is ported forward from a patch that Patrick McHardy
did for me against 2.6.31.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Acked-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Fix some comments:
    s/transmition/transmission/
    s/puting/putting/
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

This fixes a few misspellings, word repetitions, and some grammar
nits in ath5k comments.  No code changes.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>