Device losses read-reg interrupts. By looking at usbmon it appears that
USB_INT_ID_RETRY_FAILED can override USB_INT_ID_REGS. This causes read
command to timeout, usually under heavy TX.
Fix by retrying read registers again if USB_INT_ID_RETRY_FAILED is received
while waiting for USB_INT_ID_REGS.
However USB_INT_ID_REGS is not always lost but is received after
USB_INT_ID_RETRY_FAILED and is usually received by the retried read
command. USB_INT_ID_REGS of the retry is then left unhandled and might
be received by next read command. Handle this by ignoring previous
USB_INT_ID_REGS that doesn't match current read command request.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@xxxxxxxx>
---
drivers/net/wireless/zd1211rw/zd_usb.c | 125 +++++++++++++++++++++++++++-----
drivers/net/wireless/zd1211rw/zd_usb.h | 5 +
2 files changed, 109 insertions(+), 21 deletions(-)
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index 621c2cc..cf0d69d 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -111,6 +111,9 @@ MODULE_DEVICE_TABLE(usb, usb_ids);
#define FW_ZD1211_PREFIX "zd1211/zd1211_"
#define FW_ZD1211B_PREFIX "zd1211/zd1211b_"
+static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req,
+ unsigned int count);
+
/* USB device initialization */
static void int_urb_complete(struct urb *urb);
@@ -365,6 +368,20 @@ exit:
#define urb_dev(urb) (&(urb)->dev->dev)
+static inline void handle_regs_int_override(struct urb *urb)
+{
+ struct zd_usb *usb = urb->context;
+ struct zd_usb_interrupt *intr = &usb->intr;
+
+ spin_lock(&intr->lock);
+ if (atomic_read(&intr->read_regs_enabled)) {
+ atomic_set(&intr->read_regs_enabled, 0);
+ intr->read_regs_int_overridden = 1;
+ complete(&intr->read_regs.completion);
+ }
+ spin_unlock(&intr->lock);
+}
+
static inline void handle_regs_int(struct urb *urb)
{
struct zd_usb *usb = urb->context;
@@ -383,25 +400,45 @@ static inline void handle_regs_int(struct urb *urb)
USB_MAX_EP_INT_BUFFER);
spin_unlock(&mac->lock);
schedule_work(&mac->process_intr);
- } else if (intr->read_regs_enabled) {
- intr->read_regs.length = len = urb->actual_length;
-
+ } else if (atomic_read(&intr->read_regs_enabled)) {
+ len = urb->actual_length;
+ intr->read_regs.length = urb->actual_length;
if (len > sizeof(intr->read_regs.buffer))
len = sizeof(intr->read_regs.buffer);
+
memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
- intr->read_regs_enabled = 0;
+
+ /* Sometimes USB_INT_ID_REGS is not overridden, but comes after
+ * USB_INT_ID_RETRY_FAILED. Read-reg retry then gets this
+ * delayed USB_INT_ID_REGS, but leaves USB_INT_ID_REGS of
+ * retry unhandled. Next read-reg command then might catch
+ * this wrong USB_INT_ID_REGS. Fix by ignoring wrong reads.
+ */
+ if (!check_read_regs(usb, intr->read_regs.req,
+ intr->read_regs.req_count))
+ goto out;
+
+ atomic_set(&intr->read_regs_enabled, 0);
+ intr->read_regs_int_overridden = 0;
complete(&intr->read_regs.completion);
+
goto out;
}
out:
spin_unlock(&intr->lock);
+
+ /* CR_INTERRUPT might override read_reg too. */
+ if (int_num == CR_INTERRUPT && atomic_read(&intr->read_regs_enabled))
+ handle_regs_int_override(urb);
}
static void int_urb_complete(struct urb *urb)
{
int r;
struct usb_int_header *hdr;
+ struct zd_usb *usb;
+ struct zd_usb_interrupt *intr;
switch (urb->status) {
case 0:
@@ -430,6 +467,14 @@ static void int_urb_complete(struct urb *urb)
goto resubmit;
}
+ /* USB_INT_ID_RETRY_FAILED triggered by tx-urb submit can override
+ * pending USB_INT_ID_REGS causing read command timeout.
+ */
+ usb = urb->context;
+ intr = &usb->intr;
+ if (hdr->id != USB_INT_ID_REGS && atomic_read(&intr->read_regs_enabled))
+ handle_regs_int_override(urb);
+
switch (hdr->id) {
case USB_INT_ID_REGS:
handle_regs_int(urb);
@@ -1129,6 +1174,7 @@ static inline void init_usb_interrupt(struct zd_usb *usb)
spin_lock_init(&intr->lock);
intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
init_completion(&intr->read_regs.completion);
+ atomic_set(&intr->read_regs_enabled, 0);
intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
}
@@ -1563,12 +1609,16 @@ static int usb_int_regs_length(unsigned int count)
return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
}
-static void prepare_read_regs_int(struct zd_usb *usb)
+static void prepare_read_regs_int(struct zd_usb *usb,
+ struct usb_req_read_regs *req,
+ unsigned int count)
{
struct zd_usb_interrupt *intr = &usb->intr;
spin_lock_irq(&intr->lock);
- intr->read_regs_enabled = 1;
+ atomic_set(&intr->read_regs_enabled, 1);
+ intr->read_regs.req = req;
+ intr->read_regs.req_count = count;
INIT_COMPLETION(intr->read_regs.completion);
spin_unlock_irq(&intr->lock);
}
@@ -1578,22 +1628,18 @@ static void disable_read_regs_int(struct zd_usb *usb)
struct zd_usb_interrupt *intr = &usb->intr;
spin_lock_irq(&intr->lock);
- intr->read_regs_enabled = 0;
+ atomic_set(&intr->read_regs_enabled, 0);
spin_unlock_irq(&intr->lock);
}
-static int get_results(struct zd_usb *usb, u16 *values,
- struct usb_req_read_regs *req, unsigned int count)
+static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req,
+ unsigned int count)
{
- int r;
int i;
struct zd_usb_interrupt *intr = &usb->intr;
struct read_regs_int *rr = &intr->read_regs;
struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
- spin_lock_irq(&intr->lock);
-
- r = -EIO;
/* The created block size seems to be larger than expected.
* However results appear to be correct.
*/
@@ -1601,13 +1647,14 @@ static int get_results(struct zd_usb *usb, u16 *values,
dev_dbg_f(zd_usb_dev(usb),
"error: actual length %d less than expected %d\n",
rr->length, usb_int_regs_length(count));
- goto error_unlock;
+ return false;
}
+
if (rr->length > sizeof(rr->buffer)) {
dev_dbg_f(zd_usb_dev(usb),
"error: actual length %d exceeds buffer size %zu\n",
rr->length, sizeof(rr->buffer));
- goto error_unlock;
+ return false;
}
for (i = 0; i < count; i++) {
@@ -1617,8 +1664,39 @@ static int get_results(struct zd_usb *usb, u16 *values,
"rd[%d] addr %#06hx expected %#06hx\n", i,
le16_to_cpu(rd->addr),
le16_to_cpu(req->addr[i]));
- goto error_unlock;
+ return false;
}
+ }
+
+ return true;
+}
+
+static int get_results(struct zd_usb *usb, u16 *values,
+ struct usb_req_read_regs *req, unsigned int count,
+ bool *retry)
+{
+ int r;
+ int i;
+ struct zd_usb_interrupt *intr = &usb->intr;
+ struct read_regs_int *rr = &intr->read_regs;
+ struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
+
+ spin_lock_irq(&intr->lock);
+
+ r = -EIO;
+
+ /* Read failed because firmware bug? */
+ *retry = !!intr->read_regs_int_overridden;
+ if (*retry)
+ goto error_unlock;
+
+ if (!check_read_regs(usb, req, count)) {
+ dev_dbg_f(zd_usb_dev(usb), "error: invalid read regs\n");
+ goto error_unlock;
+ }
+
+ for (i = 0; i < count; i++) {
+ struct reg_data *rd = ®s->regs[i];
values[i] = le16_to_cpu(rd->value);
}
@@ -1631,11 +1709,11 @@ error_unlock:
int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
const zd_addr_t *addresses, unsigned int count)
{
- int r;
- int i, req_len, actual_req_len;
+ int r, i, req_len, actual_req_len, try_count = 0;
struct usb_device *udev;
struct usb_req_read_regs *req = NULL;
unsigned long timeout;
+ bool retry = false;
if (count < 1) {
dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
@@ -1671,8 +1749,10 @@ int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
for (i = 0; i < count; i++)
req->addr[i] = cpu_to_le16((u16)addresses[i]);
+retry_read:
+ try_count++;
udev = zd_usb_to_usbdev(usb);
- prepare_read_regs_int(usb);
+ prepare_read_regs_int(usb, req, count);
r = zd_ep_regs_out_msg(udev, req, req_len, &actual_req_len, 50 /*ms*/);
if (r) {
dev_dbg_f(zd_usb_dev(usb),
@@ -1696,7 +1776,12 @@ int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
goto error;
}
- r = get_results(usb, values, req, count);
+ r = get_results(usb, values, req, count, &retry);
+ if (retry && try_count < 20) {
+ dev_dbg_f(zd_usb_dev(usb), "read retry, tries so far: %d\n",
+ try_count);
+ goto retry_read;
+ }
error:
return r;
}
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.h b/drivers/net/wireless/zd1211rw/zd_usb.h
index bf94284..99193b4 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.h
+++ b/drivers/net/wireless/zd1211rw/zd_usb.h
@@ -144,6 +144,8 @@ struct usb_int_retry_fail {
struct read_regs_int {
struct completion completion;
+ struct usb_req_read_regs *req;
+ unsigned int req_count;
/* Stores the USB int structure and contains the USB address of the
* first requested register before request.
*/
@@ -169,7 +171,8 @@ struct zd_usb_interrupt {
void *buffer;
dma_addr_t buffer_dma;
int interval;
- u8 read_regs_enabled:1;
+ atomic_t read_regs_enabled;
+ u8 read_regs_int_overridden:1;
};
static inline struct usb_int_regs *get_read_regs(struct zd_usb_interrupt *intr)
--
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