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iwlwifi: don't panic in error path on non-msix systems

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The driver uses msix causes-register to handle both msix and non msix
interrupts when performing sync nmi.  On devices that do not support
msix this register is unmapped and accessing it causes a kernel panic.

Solve this by differentiating the two cases and accessing the proper
causes-register in each case.

Reported-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
This commit is contained in:
Shahar S Matityahu 2019-04-15 14:43:04 +03:00 committed by Luca Coelho
parent 614c70f35c
commit 1c6bca6d75
1 changed files with 13 additions and 6 deletions
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19
drivers/net/wireless/intel/iwlwifi/pcie/trans.c
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@ -3644,20 +3644,27 @@ out_no_pci:
void iwl_trans_pcie_sync_nmi(struct iwl_trans *trans)
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
unsigned long timeout = jiffies + IWL_TRANS_NMI_TIMEOUT;
u32 inta_addr, sw_err_bit;
if (trans_pcie->msix_enabled) {
inta_addr = CSR_MSIX_HW_INT_CAUSES_AD;
sw_err_bit = MSIX_HW_INT_CAUSES_REG_SW_ERR;
} else {
inta_addr = CSR_INT;
sw_err_bit = CSR_INT_BIT_SW_ERR;
}
iwl_disable_interrupts(trans);
iwl_force_nmi(trans);
while (time_after(timeout, jiffies)) {
u32 inta_hw = iwl_read32(trans,
CSR_MSIX_HW_INT_CAUSES_AD);
u32 inta_hw = iwl_read32(trans, inta_addr);
/* Error detected by uCode */
if (inta_hw & MSIX_HW_INT_CAUSES_REG_SW_ERR) {
if (inta_hw & sw_err_bit) {
/* Clear causes register */
iwl_write32(trans, CSR_MSIX_HW_INT_CAUSES_AD,
inta_hw &
MSIX_HW_INT_CAUSES_REG_SW_ERR);
iwl_write32(trans, inta_addr, inta_hw & sw_err_bit);
break;
}