kernel-ark/drivers/net/wireless/ath/ath9k/pci.c
Jouni Malinen f0214843ba ath9k: Fix PCI FATAL interrupts by restoring RETRY_TIMEOUT disabling
An earlier commit, 'ath9k: remove dummy PCI "retry timeout" fix', removed
code that was documented to disable RETRY_TIMEOUT register (PCI reg
0x41) since it was claimed to be a no-op. However, it turns out that
there are some combinations of hosts and ath9k-supported cards for
which this is not a no-op (reg 0x41 has value 0x80, not 0) and this
code (or something similar) is needed. In such cases, the driver may
be next to unusable due to very frequent PCI FATAL interrupts from the
card.

Reverting the earlier commit, i.e., restoring the RETRY_TIMEOUT
disabling, seems to resolve the issue. Since the removal of this code
was not based on any known issue and was purely a cleanup change, the
safest option here is to just revert that commit. Should there be
desire to clean this up in the future, the change will need to be
tested with a more complete coverage of cards and host systems.

http://bugzilla.kernel.org/show_bug.cgi?id=13483

Cc: stable@kernel.org
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-06-19 11:50:17 -04:00

299 lines
7.3 KiB
C

/*
* Copyright (c) 2008-2009 Atheros Communications Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/nl80211.h>
#include <linux/pci.h>
#include "ath9k.h"
static struct pci_device_id ath_pci_id_table[] __devinitdata = {
{ PCI_VDEVICE(ATHEROS, 0x0023) }, /* PCI */
{ PCI_VDEVICE(ATHEROS, 0x0024) }, /* PCI-E */
{ PCI_VDEVICE(ATHEROS, 0x0027) }, /* PCI */
{ PCI_VDEVICE(ATHEROS, 0x0029) }, /* PCI */
{ PCI_VDEVICE(ATHEROS, 0x002A) }, /* PCI-E */
{ PCI_VDEVICE(ATHEROS, 0x002B) }, /* PCI-E */
{ 0 }
};
/* return bus cachesize in 4B word units */
static void ath_pci_read_cachesize(struct ath_softc *sc, int *csz)
{
u8 u8tmp;
pci_read_config_byte(to_pci_dev(sc->dev), PCI_CACHE_LINE_SIZE,
(u8 *)&u8tmp);
*csz = (int)u8tmp;
/*
* This check was put in to avoid "unplesant" consequences if
* the bootrom has not fully initialized all PCI devices.
* Sometimes the cache line size register is not set
*/
if (*csz == 0)
*csz = DEFAULT_CACHELINE >> 2; /* Use the default size */
}
static void ath_pci_cleanup(struct ath_softc *sc)
{
struct pci_dev *pdev = to_pci_dev(sc->dev);
pci_iounmap(pdev, sc->mem);
pci_disable_device(pdev);
pci_release_region(pdev, 0);
}
static bool ath_pci_eeprom_read(struct ath_hw *ah, u32 off, u16 *data)
{
(void)REG_READ(ah, AR5416_EEPROM_OFFSET + (off << AR5416_EEPROM_S));
if (!ath9k_hw_wait(ah,
AR_EEPROM_STATUS_DATA,
AR_EEPROM_STATUS_DATA_BUSY |
AR_EEPROM_STATUS_DATA_PROT_ACCESS, 0,
AH_WAIT_TIMEOUT)) {
return false;
}
*data = MS(REG_READ(ah, AR_EEPROM_STATUS_DATA),
AR_EEPROM_STATUS_DATA_VAL);
return true;
}
static struct ath_bus_ops ath_pci_bus_ops = {
.read_cachesize = ath_pci_read_cachesize,
.cleanup = ath_pci_cleanup,
.eeprom_read = ath_pci_eeprom_read,
};
static int ath_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
void __iomem *mem;
struct ath_wiphy *aphy;
struct ath_softc *sc;
struct ieee80211_hw *hw;
u8 csz;
u32 val;
int ret = 0;
struct ath_hw *ah;
if (pci_enable_device(pdev))
return -EIO;
ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
if (ret) {
printk(KERN_ERR "ath9k: 32-bit DMA not available\n");
goto bad;
}
ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
if (ret) {
printk(KERN_ERR "ath9k: 32-bit DMA consistent "
"DMA enable failed\n");
goto bad;
}
/*
* Cache line size is used to size and align various
* structures used to communicate with the hardware.
*/
pci_read_config_byte(pdev, PCI_CACHE_LINE_SIZE, &csz);
if (csz == 0) {
/*
* Linux 2.4.18 (at least) writes the cache line size
* register as a 16-bit wide register which is wrong.
* We must have this setup properly for rx buffer
* DMA to work so force a reasonable value here if it
* comes up zero.
*/
csz = L1_CACHE_BYTES / sizeof(u32);
pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, csz);
}
/*
* The default setting of latency timer yields poor results,
* set it to the value used by other systems. It may be worth
* tweaking this setting more.
*/
pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xa8);
pci_set_master(pdev);
/*
* Disable the RETRY_TIMEOUT register (0x41) to keep
* PCI Tx retries from interfering with C3 CPU state.
*/
pci_read_config_dword(pdev, 0x40, &val);
if ((val & 0x0000ff00) != 0)
pci_write_config_dword(pdev, 0x40, val & 0xffff00ff);
ret = pci_request_region(pdev, 0, "ath9k");
if (ret) {
dev_err(&pdev->dev, "PCI memory region reserve error\n");
ret = -ENODEV;
goto bad;
}
mem = pci_iomap(pdev, 0, 0);
if (!mem) {
printk(KERN_ERR "PCI memory map error\n") ;
ret = -EIO;
goto bad1;
}
hw = ieee80211_alloc_hw(sizeof(struct ath_wiphy) +
sizeof(struct ath_softc), &ath9k_ops);
if (hw == NULL) {
printk(KERN_ERR "ath_pci: no memory for ieee80211_hw\n");
goto bad2;
}
SET_IEEE80211_DEV(hw, &pdev->dev);
pci_set_drvdata(pdev, hw);
aphy = hw->priv;
sc = (struct ath_softc *) (aphy + 1);
aphy->sc = sc;
aphy->hw = hw;
sc->pri_wiphy = aphy;
sc->hw = hw;
sc->dev = &pdev->dev;
sc->mem = mem;
sc->bus_ops = &ath_pci_bus_ops;
if (ath_attach(id->device, sc) != 0) {
ret = -ENODEV;
goto bad3;
}
/* setup interrupt service routine */
if (request_irq(pdev->irq, ath_isr, IRQF_SHARED, "ath", sc)) {
printk(KERN_ERR "%s: request_irq failed\n",
wiphy_name(hw->wiphy));
ret = -EIO;
goto bad4;
}
sc->irq = pdev->irq;
ah = sc->sc_ah;
printk(KERN_INFO
"%s: Atheros AR%s MAC/BB Rev:%x "
"AR%s RF Rev:%x: mem=0x%lx, irq=%d\n",
wiphy_name(hw->wiphy),
ath_mac_bb_name(ah->hw_version.macVersion),
ah->hw_version.macRev,
ath_rf_name((ah->hw_version.analog5GhzRev & AR_RADIO_SREV_MAJOR)),
ah->hw_version.phyRev,
(unsigned long)mem, pdev->irq);
return 0;
bad4:
ath_detach(sc);
bad3:
ieee80211_free_hw(hw);
bad2:
pci_iounmap(pdev, mem);
bad1:
pci_release_region(pdev, 0);
bad:
pci_disable_device(pdev);
return ret;
}
static void ath_pci_remove(struct pci_dev *pdev)
{
struct ieee80211_hw *hw = pci_get_drvdata(pdev);
struct ath_wiphy *aphy = hw->priv;
struct ath_softc *sc = aphy->sc;
ath_cleanup(sc);
}
#ifdef CONFIG_PM
static int ath_pci_suspend(struct pci_dev *pdev, pm_message_t state)
{
struct ieee80211_hw *hw = pci_get_drvdata(pdev);
struct ath_wiphy *aphy = hw->priv;
struct ath_softc *sc = aphy->sc;
ath9k_hw_set_gpio(sc->sc_ah, ATH_LED_PIN, 1);
pci_save_state(pdev);
pci_disable_device(pdev);
pci_set_power_state(pdev, PCI_D3hot);
return 0;
}
static int ath_pci_resume(struct pci_dev *pdev)
{
struct ieee80211_hw *hw = pci_get_drvdata(pdev);
struct ath_wiphy *aphy = hw->priv;
struct ath_softc *sc = aphy->sc;
u32 val;
int err;
err = pci_enable_device(pdev);
if (err)
return err;
pci_restore_state(pdev);
/*
* Suspend/Resume resets the PCI configuration space, so we have to
* re-disable the RETRY_TIMEOUT register (0x41) to keep
* PCI Tx retries from interfering with C3 CPU state
*/
pci_read_config_dword(pdev, 0x40, &val);
if ((val & 0x0000ff00) != 0)
pci_write_config_dword(pdev, 0x40, val & 0xffff00ff);
/* Enable LED */
ath9k_hw_cfg_output(sc->sc_ah, ATH_LED_PIN,
AR_GPIO_OUTPUT_MUX_AS_OUTPUT);
ath9k_hw_set_gpio(sc->sc_ah, ATH_LED_PIN, 1);
return 0;
}
#endif /* CONFIG_PM */
MODULE_DEVICE_TABLE(pci, ath_pci_id_table);
static struct pci_driver ath_pci_driver = {
.name = "ath9k",
.id_table = ath_pci_id_table,
.probe = ath_pci_probe,
.remove = ath_pci_remove,
#ifdef CONFIG_PM
.suspend = ath_pci_suspend,
.resume = ath_pci_resume,
#endif /* CONFIG_PM */
};
int ath_pci_init(void)
{
return pci_register_driver(&ath_pci_driver);
}
void ath_pci_exit(void)
{
pci_unregister_driver(&ath_pci_driver);
}