2016-07-01 13:21:08

by Amitkumar Karwar

Subject: [PATCH] mwifiex: fix interrupt processing corner case in MSI mode

From: Shengzhen Li <[email protected]>

As interrupt is read in interrupt handler as well as interrupt processing
thread, we observed a corner case issue for MSI in which interrupt gets
processed twice.

This patch moves interrupt reading code for MSI mode from
mwifiex_interrupt_status() to mwifiex_pcie_process_int() to avoid the
issue.

Signed-off-by: Shengzhen Li <[email protected]>
Signed-off-by: Amitkumar Karwar <[email protected]>
---
drivers/net/wireless/marvell/mwifiex/pcie.c | 50 ++++++++++++++++++++++++++---
1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
index 7b17389..2c64b99 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -2086,6 +2086,13 @@ static void mwifiex_interrupt_status(struct mwifiex_adapter *adapter,
unsigned long flags;
struct pcie_service_card *card = adapter->card;

+ if (card->msi_enable) {
+ spin_lock_irqsave(&adapter->int_lock, flags);
+ adapter->int_status = 1;
+ spin_unlock_irqrestore(&adapter->int_lock, flags);
+ return;
+ }
+
if (!mwifiex_pcie_ok_to_access_hw(adapter))
return;

@@ -2187,15 +2194,44 @@ exit:
static int mwifiex_process_pcie_int(struct mwifiex_adapter *adapter)
{
int ret;
- u32 pcie_ireg;
+ u32 pcie_ireg = 0;
unsigned long flags;
+ struct pcie_service_card *card = adapter->card;

spin_lock_irqsave(&adapter->int_lock, flags);
- /* Clear out unused interrupts */
- pcie_ireg = adapter->int_status;
+ if (!card->msi_enable) {
+ /* Clear out unused interrupts */
+ pcie_ireg = adapter->int_status;
+ }
adapter->int_status = 0;
spin_unlock_irqrestore(&adapter->int_lock, flags);

+ if (card->msi_enable) {
+ if (mwifiex_pcie_ok_to_access_hw(adapter)) {
+ if (mwifiex_read_reg(adapter, PCIE_HOST_INT_STATUS,
+ &pcie_ireg)) {
+ mwifiex_dbg(adapter, ERROR,
+ "Read register failed\n");
+ return -1;
+ }
+
+ if ((pcie_ireg != 0xFFFFFFFF) && (pcie_ireg)) {
+ if (mwifiex_write_reg(adapter,
+ PCIE_HOST_INT_STATUS,
+ ~pcie_ireg)) {
+ mwifiex_dbg(adapter, ERROR,
+ "Write register failed\n");
+ return -1;
+ }
+ if (!adapter->pps_uapsd_mode &&
+ adapter->ps_state == PS_STATE_SLEEP) {
+ adapter->ps_state = PS_STATE_AWAKE;
+ adapter->pm_wakeup_fw_try = false;
+ del_timer(&adapter->wakeup_timer);
+ }
+ }
+ }
+ }
while (pcie_ireg & HOST_INTR_MASK) {
if (pcie_ireg & HOST_INTR_DNLD_DONE) {
pcie_ireg &= ~HOST_INTR_DNLD_DONE;
@@ -2235,6 +2271,12 @@ static int mwifiex_process_pcie_int(struct mwifiex_adapter *adapter)
return ret;
}

+ if (card->msi_enable) {
+ spin_lock_irqsave(&adapter->int_lock, flags);
+ adapter->int_status = 0;
+ spin_unlock_irqrestore(&adapter->int_lock, flags);
+ }
+
if (mwifiex_pcie_ok_to_access_hw(adapter)) {
if (mwifiex_read_reg(adapter, PCIE_HOST_INT_STATUS,
&pcie_ireg)) {
@@ -2258,7 +2300,7 @@ static int mwifiex_process_pcie_int(struct mwifiex_adapter *adapter)
mwifiex_dbg(adapter, INTR,
"info: cmd_sent=%d data_sent=%d\n",
adapter->cmd_sent, adapter->data_sent);
- if (adapter->ps_state != PS_STATE_SLEEP)
+ if (!card->msi_enable && adapter->ps_state != PS_STATE_SLEEP)
mwifiex_pcie_enable_host_int(adapter);

return 0;
--
1.9.1

2016-07-08 13:49:28

by Kalle Valo

Subject: Re: mwifiex: fix interrupt processing corner case in MSI mode

Amitkumar Karwar <[email protected]> wrote:
> From: Shengzhen Li <[email protected]>
>
> As interrupt is read in interrupt handler as well as interrupt processing
> thread, we observed a corner case issue for MSI in which interrupt gets
> processed twice.
>
> This patch moves interrupt reading code for MSI mode from
> mwifiex_interrupt_status() to mwifiex_pcie_process_int() to avoid the
> issue.
>
> Signed-off-by: Shengzhen Li <[email protected]>
> Signed-off-by: Amitkumar Karwar <[email protected]>

Thanks, 1 patch applied to wireless-drivers-next.git:

5781fc29dbbd mwifiex: fix interrupt processing corner case in MSI mode

--
Sent by pwcli
https://patchwork.kernel.org/patch/9209885/