lkml.org 
[lkml]   [2020]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 5.4 405/459] ath10k: pci: Only dump ATH10K_MEM_REGION_TYPE_IOREG when safe
Date
From: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

[ Upstream commit d239380196c4e27a26fa4bea73d2bf994c14ec2d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/ath10k/pci.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index 347bb92e4130d..0a727502d14c5 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);
--
2.20.1
\
 
 \ /
  Last update: 2020-02-14 18:21    [W:0.887 / U:8.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site