brcmfmac: send mailbox interrupt twice for specific hardware device

For PCIE wireless device with core revision less than 14, device may miss
PCIE to System Backplane Interrupt via PCIEtoSBMailbox. So add sending
mail box interrupt twice as a hardware workaround.
Signed-off-by: Wright Feng <wright.feng@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c

@@ -675,6 +675,7 @@ static int
 brcmf_pcie_send_mb_data(struct brcmf_pciedev_info *devinfo, u32 htod_mb_data)
 {
 	struct brcmf_pcie_shared_info *shared;
+	struct brcmf_core *core;
 	u32 addr;
 	u32 cur_htod_mb_data;
 	u32 i;
@@ -698,7 +699,11 @@ brcmf_pcie_send_mb_data(struct brcmf_pciedev_info *devinfo, u32 htod_mb_data)
 
 	brcmf_pcie_write_tcm32(devinfo, addr, htod_mb_data);
 	pci_write_config_dword(devinfo->pdev, BRCMF_PCIE_REG_SBMBX, 1);
-	pci_write_config_dword(devinfo->pdev, BRCMF_PCIE_REG_SBMBX, 1);
+
+	/* Send mailbox interrupt twice as a hardware workaround */
+	core = brcmf_chip_get_core(devinfo->ci, BCMA_CORE_PCIE2);
+	if (core->rev <= 13)
+		pci_write_config_dword(devinfo->pdev, BRCMF_PCIE_REG_SBMBX, 1);
 
 	return 0;
 }