ath9k: skip ->config_pci_powersave() if PCIe port has ASPM disabled

We receive many bug reports about system hang during suspend/resume
when ath9k driver is in use. Adrian Chadd remarked that this problem
happens on systems that have ASPM disabled.

To do not hit the bug, skip doing ->config_pci_powersave magic if PCIe
downstream port device, which ath9k device is connected to, has ASPM
disabled.

Bug was introduced by:

commit 53bc7aa08b
Author: Vivek Natarajan <vnatarajan@atheros.com>
Date:   Mon Apr 5 14:48:04 2010 +0530

    ath9k: Add support for newer AR9285 chipsets.

Patch should address:
https://bugzilla.kernel.org/show_bug.cgi?id=37462
https://bugzilla.kernel.org/show_bug.cgi?id=37082
https://bugzilla.redhat.com/show_bug.cgi?id=697157

however I did not receive confirmation about that, except from Camilo
Mesias, whose system stops hang regularly with this patch (but still
hangs from time to time, but this is probably some other bug).

Tested-by: Camilo Mesias <camilo@mesias.co.uk>
Cc: stable@kernel.org # 2.6.35+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Stanislaw Gruszka
2011-07-29 15:59:08 +02:00
committed by John W. Linville
parent 84404623da
commit d4930086bd
5 changed files with 40 additions and 13 deletions

View File

@@ -16,6 +16,7 @@
#include <linux/nl80211.h>
#include <linux/pci.h>
#include <linux/pci-aspm.h>
#include <linux/ath9k_platform.h>
#include "ath9k.h"
@@ -115,12 +116,38 @@ static void ath_pci_extn_synch_enable(struct ath_common *common)
pci_write_config_byte(pdev, sc->sc_ah->caps.pcie_lcr_offset, lnkctl);
}
static void ath_pci_aspm_init(struct ath_common *common)
{
struct ath_softc *sc = (struct ath_softc *) common->priv;
struct ath_hw *ah = sc->sc_ah;
struct pci_dev *pdev = to_pci_dev(sc->dev);
struct pci_dev *parent;
int pos;
u8 aspm;
if (!pci_is_pcie(pdev))
return;
parent = pdev->bus->self;
if (WARN_ON(!parent))
return;
pos = pci_pcie_cap(parent);
pci_read_config_byte(parent, pos + PCI_EXP_LNKCTL, &aspm);
if (aspm & (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1)) {
ah->aspm_enabled = true;
/* Initialize PCIe PM and SERDES registers. */
ath9k_hw_configpcipowersave(ah, 0, 0);
}
}
static const struct ath_bus_ops ath_pci_bus_ops = {
.ath_bus_type = ATH_PCI,
.read_cachesize = ath_pci_read_cachesize,
.eeprom_read = ath_pci_eeprom_read,
.bt_coex_prep = ath_pci_bt_coex_prep,
.extn_synch_en = ath_pci_extn_synch_enable,
.aspm_init = ath_pci_aspm_init,
};
static int ath_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)