USB: musb: host side diagnostics tweaks

Random host-side MUSB updates, mostly relating to better diagnostics:

 + Improve diagnostics on host side:
    - tx flush fifo:
       * Avoid hundreds of duplicate TX FIFONOTEMPTY messages
       * make "Can't flush TX fifo" a warning, and say which endpoint
    - giveback:
       * use correct status code
       * show completion function name not just URB pointer
    - Fix annoying "1 bytes" (should be "1 byte")

 + Be more consistent about failing init of unusable fifo_mode

It's not clear why that "can't flush TX fifo" message appears, though
it might relate to disconnection; I see it not infrequently

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 15 insertions, 11 deletions

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index de7f8bec6bde..8b14437331c7 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1212,7 +1212,7 @@ static int __init ep_config_from_table(struct musb *musb)
                 if (epn >= musb->config->num_eps) {
                         pr_debug("%s: invalid ep %d\n",
                                         musb_driver_name, epn);
-                        continue;
+                        return -EINVAL;
                 }
                 offset = fifo_setup(musb, hw_ep + epn, cfg++, offset);
                 if (offset < 0) {
@@ -1813,7 +1813,6 @@ allocate_instance(struct device *dev,
         for (epnum = 0, ep = musb->endpoints;
                         epnum < musb->config->num_eps;
                         epnum++, ep++) {
-
                 ep->musb = musb;
                 ep->epnum = epnum;
         }
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index cc64462d4c4e..bf25ef4cc151 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -112,18 +112,21 @@ static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
 {
         void __iomem    *epio = ep->regs;
         u16             csr;
+        u16             lastcsr = 0;
         int             retries = 1000;
 
         csr = musb_readw(epio, MUSB_TXCSR);
         while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
-                DBG(5, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
+                if (csr != lastcsr)
+                        DBG(3, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
+                lastcsr = csr;
                 csr |= MUSB_TXCSR_FLUSHFIFO;
                 musb_writew(epio, MUSB_TXCSR, csr);
                 csr = musb_readw(epio, MUSB_TXCSR);
-                if (retries-- < 1) {
-                        ERR("Could not flush host TX fifo: csr: %04x\n", csr);
+                if (WARN(retries-- < 1,
+                                "Could not flush host TX%d fifo: csr: %04x\n",
+                                ep->epnum, csr))
                         return;
-                }
                 mdelay(1);
         }
 }
@@ -268,7 +271,7 @@ __musb_giveback(struct musb *musb, struct urb *urb, int status)
 __releases(musb->lock)
 __acquires(musb->lock)
 {
-        DBG(({ int level; switch (urb->status) {
+        DBG(({ int level; switch (status) {
                                 case 0:
                                         level = 4;
                                         break;
@@ -283,8 +286,8 @@ __acquires(musb->lock)
                                         level = 2;
                                         break;
                                 }; level; }),
-                        "complete %p (%d), dev%d ep%d%s, %d/%d\n",
-                        urb, urb->status,
+                        "complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
+                        urb, urb->complete, status,
                         usb_pipedevice(urb->pipe),
                         usb_pipeendpoint(urb->pipe),
                         usb_pipein(urb->pipe) ? "in" : "out",
@@ -988,8 +991,10 @@ static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
                 if (fifo_count) {
                         fifo_dest = (u8 *) (urb->transfer_buffer
                                         + urb->actual_length);
-                        DBG(3, "Sending %d bytes to %p\n",
-                                        fifo_count, fifo_dest);
+                        DBG(3, "Sending %d byte%s to ep0 fifo %p\n",
+                                        fifo_count,
+                                        (fifo_count == 1) ? "" : "s",
+                                        fifo_dest);
                         musb_write_fifo(hw_ep, fifo_count, fifo_dest);
 
                         urb->actual_length += fifo_count;