[PATCH] habanalabs: add more protection of device during reset

From: Oded Gabbay
Date: Mon Nov 18 2019 - 08:06:45 EST


Prevent accesses to the device (register read/write) from debugfs entries
during reset as that can cause the device to get stuck.

Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
---
drivers/misc/habanalabs/debugfs.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/misc/habanalabs/debugfs.c b/drivers/misc/habanalabs/debugfs.c
index 1cf75010a379..20413e350343 100644
--- a/drivers/misc/habanalabs/debugfs.c
+++ b/drivers/misc/habanalabs/debugfs.c
@@ -528,6 +528,12 @@ static int engines_show(struct seq_file *s, void *data)
struct hl_dbg_device_entry *dev_entry = entry->dev_entry;
struct hl_device *hdev = dev_entry->hdev;

+ if (atomic_read(&hdev->in_reset)) {
+ dev_warn_ratelimited(hdev->dev,
+ "Can't check device idle during reset\n");
+ return 0;
+ }
+
hdev->asic_funcs->is_device_idle(hdev, NULL, s);

return 0;
@@ -640,6 +646,11 @@ static ssize_t hl_data_read32(struct file *f, char __user *buf,
u32 val;
ssize_t rc;

+ if (atomic_read(&hdev->in_reset)) {
+ dev_warn_ratelimited(hdev->dev, "Can't read during reset\n");
+ return 0;
+ }
+
if (*ppos)
return 0;

@@ -669,6 +680,11 @@ static ssize_t hl_data_write32(struct file *f, const char __user *buf,
u32 value;
ssize_t rc;

+ if (atomic_read(&hdev->in_reset)) {
+ dev_warn_ratelimited(hdev->dev, "Can't write during reset\n");
+ return 0;
+ }
+
rc = kstrtouint_from_user(buf, count, 16, &value);
if (rc)
return rc;
--
2.17.1