From: Brian Norris Date: Wed, 23 Nov 2016 02:39:45 +0000 (-0800) Subject: mwifiex: pcie: implement timeout loop for FW programming doorbell X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=22dde1ed5a48a570aaed5ead4c7efee174f75e2e;p=openwrt%2Fstaging%2Fblogic.git mwifiex: pcie: implement timeout loop for FW programming doorbell Marvell Wifi PCIe modules don't always behave nicely for PCIe power management when their firmware hasn't been loaded, particularly after suspending the PCIe link one or more times. When this happens, we might end up spinning forever in this status-polling tight loop. Let's make this less tight by adding a timeout and by sleeping a bit in between reads, as we do with the other similar loops. This prevents us from hogging a CPU even in such pathological cases, and allows the FW initialization to just fail gracefully instead. I chose the same polling parameters as the earlier loop in this function, and empirically, I found that this loop never makes it more than about 12 cycles in a sane FW init sequence. I had no official information on the actual intended latency for this portion of the download. Signed-off-by: Brian Norris Acked-by: Amitkumar Karwar Signed-off-by: Kalle Valo --- diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c index e4f1f5575975..4db07da81d8d 100644 --- a/drivers/net/wireless/marvell/mwifiex/pcie.c +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c @@ -2051,7 +2051,7 @@ static int mwifiex_prog_fw_w_helper(struct mwifiex_adapter *adapter, } /* Wait for the command done interrupt */ - do { + for (tries = 0; tries < MAX_POLL_TRIES; tries++) { if (mwifiex_read_reg(adapter, PCIE_CPU_INT_STATUS, &ireg_intr)) { mwifiex_dbg(adapter, ERROR, @@ -2063,8 +2063,18 @@ static int mwifiex_prog_fw_w_helper(struct mwifiex_adapter *adapter, ret = -1; goto done; } - } while ((ireg_intr & CPU_INTR_DOOR_BELL) == - CPU_INTR_DOOR_BELL); + if (!(ireg_intr & CPU_INTR_DOOR_BELL)) + break; + usleep_range(10, 20); + } + if (ireg_intr & CPU_INTR_DOOR_BELL) { + mwifiex_dbg(adapter, ERROR, "%s: Card failed to ACK download\n", + __func__); + mwifiex_unmap_pci_memory(adapter, skb, + PCI_DMA_TODEVICE); + ret = -1; + goto done; + } mwifiex_unmap_pci_memory(adapter, skb, PCI_DMA_TODEVICE);