From: Jakub Kicinski <kubakici@xxxxx>
DMA to variables located on the stack is a bad idea.
For simplicity and to avoid frequent allocations create
a buffer inside the device structure. Protect this
buffer with vendor_req_mutex. Don't protect vendor
requests which don't use this buffer.
Signed-off-by: Jakub Kicinski <kubakici@xxxxx>
---
drivers/net/wireless/mediatek/mt7601u/mt7601u.h | 4 +-
drivers/net/wireless/mediatek/mt7601u/usb.c | 63 ++++++++++++-------------
drivers/net/wireless/mediatek/mt7601u/usb.h | 2 +
3 files changed, 34 insertions(+), 35 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt7601u/mt7601u.h b/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
index 9102be6b95cb..6bdfc1103fcc 100644
--- a/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
+++ b/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
@@ -146,7 +146,7 @@ enum {
* @rx_lock: protects @rx_q.
* @con_mon_lock: protects @ap_bssid, @bcn_*, @avg_rssi.
* @mutex: ensures exclusive access from mac80211 callbacks.
- * @vendor_req_mutex: ensures atomicity of vendor requests.
+ * @vendor_req_mutex: protects @vend_buf, ensures atomicity of split writes.
* @reg_atomic_mutex: ensures atomicity of indirect register accesses
* (accesses to RF and BBP).
* @hw_atomic_mutex: ensures exclusive access to HW during critical
@@ -184,6 +184,8 @@ struct mt7601u_dev {
struct mt7601u_eeprom_params *ee;
struct mutex vendor_req_mutex;
+ void *vend_buf;
+
struct mutex reg_atomic_mutex;
struct mutex hw_atomic_mutex;
diff --git a/drivers/net/wireless/mediatek/mt7601u/usb.c b/drivers/net/wireless/mediatek/mt7601u/usb.c
index 54dba4001865..416c6045ff31 100644
--- a/drivers/net/wireless/mediatek/mt7601u/usb.c
+++ b/drivers/net/wireless/mediatek/mt7601u/usb.c
@@ -92,10 +92,9 @@ void mt7601u_complete_urb(struct urb *urb)
complete(cmpl);
}
-static int
-__mt7601u_vendor_request(struct mt7601u_dev *dev, const u8 req,
- const u8 direction, const u16 val, const u16 offset,
- void *buf, const size_t buflen)
+int mt7601u_vendor_request(struct mt7601u_dev *dev, const u8 req,
+ const u8 direction, const u16 val, const u16 offset,
+ void *buf, const size_t buflen)
{
int i, ret;
struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
@@ -110,6 +109,8 @@ __mt7601u_vendor_request(struct mt7601u_dev *dev, const u8 req,
trace_mt_vend_req(dev, pipe, req, req_type, val, offset,
buf, buflen, ret);
+ if (ret == -ENODEV)
+ set_bit(MT7601U_STATE_REMOVED, &dev->state);
if (ret >= 0 || ret == -ENODEV)
return ret;
@@ -122,25 +123,6 @@ __mt7601u_vendor_request(struct mt7601u_dev *dev, const u8 req,
return ret;
}
-int
-mt7601u_vendor_request(struct mt7601u_dev *dev, const u8 req,
- const u8 direction, const u16 val, const u16 offset,
- void *buf, const size_t buflen)
-{
- int ret;
-
- mutex_lock(&dev->vendor_req_mutex);
-
- ret = __mt7601u_vendor_request(dev, req, direction, val, offset,
- buf, buflen);
- if (ret == -ENODEV)
- set_bit(MT7601U_STATE_REMOVED, &dev->state);
-
- mutex_unlock(&dev->vendor_req_mutex);
-
- return ret;
-}
-
void mt7601u_vendor_reset(struct mt7601u_dev *dev)
{
mt7601u_vendor_request(dev, MT_VEND_DEV_MODE, USB_DIR_OUT,
@@ -150,19 +132,21 @@ void mt7601u_vendor_reset(struct mt7601u_dev *dev)
u32 mt7601u_rr(struct mt7601u_dev *dev, u32 offset)
{
int ret;
- __le32 reg;
- u32 val;
+ u32 val = ~0;
WARN_ONCE(offset > USHRT_MAX, "read high off:%08x", offset);
+ mutex_lock(&dev->vendor_req_mutex);
+
ret = mt7601u_vendor_request(dev, MT_VEND_MULTI_READ, USB_DIR_IN,
- 0, offset, ®, sizeof(reg));
- val = le32_to_cpu(reg);
- if (ret > 0 && ret != sizeof(reg)) {
+ 0, offset, dev->vend_buf, MT_VEND_BUF);
+ if (ret == MT_VEND_BUF)
+ val = get_unaligned_le32(dev->vend_buf);
+ else if (ret > 0)
dev_err(dev->dev, "Error: wrong size read:%d off:%08x\n",
ret, offset);
- val = ~0;
- }
+
+ mutex_unlock(&dev->vendor_req_mutex);
trace_reg_read(dev, offset, val);
return val;
@@ -173,12 +157,17 @@ int mt7601u_vendor_single_wr(struct mt7601u_dev *dev, const u8 req,
{
int ret;
+ mutex_lock(&dev->vendor_req_mutex);
+
ret = mt7601u_vendor_request(dev, req, USB_DIR_OUT,
val & 0xffff, offset, NULL, 0);
- if (ret)
- return ret;
- return mt7601u_vendor_request(dev, req, USB_DIR_OUT,
- val >> 16, offset + 2, NULL, 0);
+ if (!ret)
+ ret = mt7601u_vendor_request(dev, req, USB_DIR_OUT,
+ val >> 16, offset + 2, NULL, 0);
+
+ mutex_unlock(&dev->vendor_req_mutex);
+
+ return ret;
}
void mt7601u_wr(struct mt7601u_dev *dev, u32 offset, u32 val)
@@ -275,6 +264,12 @@ static int mt7601u_probe(struct usb_interface *usb_intf,
usb_set_intfdata(usb_intf, dev);
+ dev->vend_buf = devm_kmalloc(dev->dev, MT_VEND_BUF, GFP_KERNEL);
+ if (!dev->vend_buf) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
ret = mt7601u_assign_pipes(usb_intf, dev);
if (ret)
goto err;
diff --git a/drivers/net/wireless/mediatek/mt7601u/usb.h b/drivers/net/wireless/mediatek/mt7601u/usb.h
index 49e188fa3798..bc182022b9d6 100644
--- a/drivers/net/wireless/mediatek/mt7601u/usb.h
+++ b/drivers/net/wireless/mediatek/mt7601u/usb.h
@@ -23,6 +23,8 @@
#define MT_VEND_DEV_MODE_RESET 1
+#define MT_VEND_BUF sizeof(__le32)
+
enum mt_vendor_req {
MT_VEND_DEV_MODE = 1,
MT_VEND_WRITE = 2,
--
2.1.0
--
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