[1/2] ath10k: pci: Only dump ATH10K_MEM_REGION_TYPE_IOREG when safe
diff mbox series

Message ID 20191219131539.1003793-2-bryan.odonoghue@linaro.org
State Accepted
Commit d239380196c4e27a26fa4bea73d2bf994c14ec2d
Delegated to: Kalle Valo
Headers show
Series
  • ath10k: pci: Two PCI related fixups
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Commit Message

Bryan O'Donoghue Dec. 19, 2019, 1:15 p.m. UTC
ath10k_pci_dump_memory_reg() will try to access memory of type
ATH10K_MEM_REGION_TYPE_IOREG however, if a hardware restart is in progress
this can crash a system.

Individual ioread32() time has been observed to jump from 15-20 ticks to >
80k ticks followed by a secure-watchdog bite and a system reset.

Work around this corner case by only issuing the read transaction when the
driver state is ATH10K_STATE_ON.

Fixes: 219cc084c6706 ("ath10k: add memory dump support QCA9984")
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 drivers/net/wireless/ath/ath10k/pci.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

Comments

Kalle Valo Dec. 19, 2019, 1:53 p.m. UTC | #1
Bryan O'Donoghue <bryan.odonoghue@linaro.org> writes:

> ath10k_pci_dump_memory_reg() will try to access memory of type
> ATH10K_MEM_REGION_TYPE_IOREG however, if a hardware restart is in progress
> this can crash a system.
>
> Individual ioread32() time has been observed to jump from 15-20 ticks to >
> 80k ticks followed by a secure-watchdog bite and a system reset.
>
> Work around this corner case by only issuing the read transaction when the
> driver state is ATH10K_STATE_ON.
>
> Fixes: 219cc084c6706 ("ath10k: add memory dump support QCA9984")
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

What ath10k hardware and firmware did you test this on? I can add that
to the commit log.
Bryan O'Donoghue Dec. 19, 2019, 2:15 p.m. UTC | #2
On 19/12/2019 13:53, Kalle Valo wrote:
> Bryan O'Donoghue <bryan.odonoghue@linaro.org> writes:
> 
>> ath10k_pci_dump_memory_reg() will try to access memory of type
>> ATH10K_MEM_REGION_TYPE_IOREG however, if a hardware restart is in progress
>> this can crash a system.
>>
>> Individual ioread32() time has been observed to jump from 15-20 ticks to >
>> 80k ticks followed by a secure-watchdog bite and a system reset.
>>
>> Work around this corner case by only issuing the read transaction when the
>> driver state is ATH10K_STATE_ON.
>>
>> Fixes: 219cc084c6706 ("ath10k: add memory dump support QCA9984")
>> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> 
> What ath10k hardware and firmware did you test this on? I can add that
> to the commit log.
> 

HW = QCA9988
FW = ??

Not quite sure how to find the firmware version TBH
Kalle Valo Dec. 19, 2019, 2:21 p.m. UTC | #3
Bryan O'Donoghue <bryan.odonoghue@linaro.org> writes:

> On 19/12/2019 13:53, Kalle Valo wrote:
>> Bryan O'Donoghue <bryan.odonoghue@linaro.org> writes:
>>
>>> ath10k_pci_dump_memory_reg() will try to access memory of type
>>> ATH10K_MEM_REGION_TYPE_IOREG however, if a hardware restart is in progress
>>> this can crash a system.
>>>
>>> Individual ioread32() time has been observed to jump from 15-20 ticks to >
>>> 80k ticks followed by a secure-watchdog bite and a system reset.
>>>
>>> Work around this corner case by only issuing the read transaction when the
>>> driver state is ATH10K_STATE_ON.
>>>
>>> Fixes: 219cc084c6706 ("ath10k: add memory dump support QCA9984")
>>> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
>>
>> What ath10k hardware and firmware did you test this on? I can add that
>> to the commit log.
>>
>
> HW = QCA9988
> FW = ??
>
> Not quite sure how to find the firmware version TBH

'dmesg | grep ath10k' should show it.
Bryan O'Donoghue Dec. 19, 2019, 2:29 p.m. UTC | #4
On 19/12/2019 14:21, Kalle Valo wrote:
> 'dmesg | grep ath10k' should show it.


[    6.579772] ath10k_pci 0000:01:00.0: firmware ver 10.4-3.9.0.2-00044 
api 5 features 
no-p2p,mfp,peer-flow-ctrl,btcoex-param,allows-mesh-bcast,no-ps crc32 
c3e1b393
Kalle Valo Jan. 26, 2020, 10:23 a.m. UTC | #5
Bryan O'Donoghue <bryan.odonoghue@linaro.org> wrote:

> ath10k_pci_dump_memory_reg() will try to access memory of type
> ATH10K_MEM_REGION_TYPE_IOREG however, if a hardware restart is in progress
> this can crash a system.
> 
> Individual ioread32() time has been observed to jump from 15-20 ticks to >
> 80k ticks followed by a secure-watchdog bite and a system reset.
> 
> Work around this corner case by only issuing the read transaction when the
> driver state is ATH10K_STATE_ON.
> 
> Tested-on: QCA9988 PCI 10.4-3.9.0.2-00044
> 
> Fixes: 219cc084c6706 ("ath10k: add memory dump support QCA9984")
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

2 patches applied to ath-next branch of ath.git, thanks.

d239380196c4 ath10k: pci: Only dump ATH10K_MEM_REGION_TYPE_IOREG when safe
63ec5cbc31f7 ath10k: pci: Fix comment on ath10k_pci_dump_memory_sram

Patch
diff mbox series

diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index bb44f5a0941b..4822a65f6f3c 100644
--- a/drivers/net/wireless/ath/ath10k/pci.c
+++ b/drivers/net/wireless/ath/ath10k/pci.c
@@ -1604,11 +1604,22 @@  static int ath10k_pci_dump_memory_reg(struct ath10k *ar,
 {
 	struct ath10k_pci *ar_pci = ath10k_pci_priv(ar);
 	u32 i;
+	int ret;
+
+	mutex_lock(&ar->conf_mutex);
+	if (ar->state != ATH10K_STATE_ON) {
+		ath10k_warn(ar, "Skipping pci_dump_memory_reg invalid state\n");
+		ret = -EIO;
+		goto done;
+	}
 
 	for (i = 0; i < region->len; i += 4)
 		*(u32 *)(buf + i) = ioread32(ar_pci->mem + region->start + i);
 
-	return region->len;
+	ret = region->len;
+done:
+	mutex_unlock(&ar->conf_mutex);
+	return ret;
 }
 
 /* if an error happened returns < 0, otherwise the length */
@@ -1704,7 +1715,11 @@  static void ath10k_pci_dump_memory(struct ath10k *ar,
 			count = ath10k_pci_dump_memory_sram(ar, current_region, buf);
 			break;
 		case ATH10K_MEM_REGION_TYPE_IOREG:
-			count = ath10k_pci_dump_memory_reg(ar, current_region, buf);
+			ret = ath10k_pci_dump_memory_reg(ar, current_region, buf);
+			if (ret < 0)
+				break;
+
+			count = ret;
 			break;
 		default:
 			ret = ath10k_pci_dump_memory_generic(ar, current_region, buf);