port-arm32/47765: Patches for src/sys/ic/smc91cxx.c

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>Number:         47765
>Category:       port-arm32
>Synopsis:       Patches for src/sys/ic/smc91cxx.c
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-arm32-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 25 07:15:00 +0000 2013
>Originator:     Robert Sprowson
>Release:        N/A
>Organization:
N/A
>Environment:
N/A
>Description:
Have recently been porting the smc91cxx driver to another platform and have a 
few fixes for it to feed back, see patch below. Change details are as follows.

Line 126, 146, 158:
Mark tables as static to remove compiler warning.

Line 494:
Resolve the correct reset recovery time. The slowest of the chips supported is 
the 91C111 which requires 50ms for its PHY to reset. The reset pulse itself can 
be very short, but is set to arbitrary 5us here.

Line 709, 812:
Spelling mistakes ammended.

Line 1022, 1160:
When performing a read from the FIFO there must be a delay of at least 375ns 
after changing the FIFO pointer to allow it to preload. Add that delay (well, 
1000ns, since delay() isn't that fine).

Line 1097:
Missing interrupt ACK write meant that this would hang the machine with an 
interrupt jammed on. This has not surfaced before because in NetBSD the 
internal MII interrupts are never unmasked so this code never fires, instead 
relying on the 1s mii_tick polling. In my port I don't poll, which exposed this 
problem.

Line 1244:
Dead variable 'dp' removed.

Line 1298:
The read of packetno is repeated at the label 'again', so no need to do it 
twice. Just goto 'again'.
>How-To-Repeat:

>Fix:
--- smc91cxx_183.c      Tue Feb 05 22:50:34 2013
+++ smc91cxx_new.c      Thu Apr 25 06:49:32 2013
@@ -126,7 +126,7 @@
 /* XXX Hardware padding doesn't work yet(?) */
 #define        SMC91CXX_SW_PAD
 
-const char *smc91cxx_idstrs[] = {
+static const char *smc91cxx_idstrs[] = {
        NULL,                           /* 0 */
        NULL,                           /* 1 */
        NULL,                           /* 2 */
@@ -146,7 +146,7 @@
 };
 
 /* Supported media types. */
-const int smc91cxx_media[] = {
+static const int smc91cxx_media[] = {
        IFM_ETHER|IFM_10_T,
        IFM_ETHER|IFM_10_5,
 };
@@ -158,7 +158,7 @@
 u_int32_t smc91cxx_mii_bitbang_read(device_t);
 void smc91cxx_mii_bitbang_write(device_t, u_int32_t);
 
-const struct mii_bitbang_ops smc91cxx_mii_bitbang_ops = {
+static const struct mii_bitbang_ops smc91cxx_mii_bitbang_ops = {
        smc91cxx_mii_bitbang_read,
        smc91cxx_mii_bitbang_write,
        {
@@ -494,16 +494,14 @@
 
        /*
         * This resets the registers mostly to defaults, but doesn't
-        * affect the EEPROM.  After the reset cycle, we pause briefly
-        * for the chip to recover.
-        *
-        * XXX how long are we really supposed to delay?  --thorpej
+        * affect the EEPROM.  The longest reset recovery time of those devices
+        * supported is the 91C111. Section 7.8 of its datasheet asks for 50ms.
         */
        SMC_SELECT_BANK(sc, 0);
        bus_space_write_2(bst, bsh, RECV_CONTROL_REG_W, RCR_SOFTRESET);
-       delay(100);
+       delay(5);
        bus_space_write_2(bst, bsh, RECV_CONTROL_REG_W, 0);
-       delay(200);
+       delay(50000);
 
        bus_space_write_2(bst, bsh, TXMIT_CONTROL_REG_W, 0);
 
@@ -709,7 +707,7 @@
        if (packetno & ARR_FAILED || timo == 0) {
                /*
                 * No transmit memory is available.  Record the number
-                * of requestd pages and enable the allocation completion
+                * of requested pages and enable the allocation completion
                 * interrupt.  Set up the watchdog timer in case we miss
                 * the interrupt.  Mark the interface as active so that
                 * no one else attempts to transmit while we're allocating
@@ -812,7 +810,7 @@
 
  readcheck:
        /*
-        * Check for incoming pcakets.  We don't want to overflow the small
+        * Check for incoming packets.  We don't want to overflow the small
         * RX FIFO.  If nothing has arrived, attempt to queue another
         * transmit packet.
         */
@@ -1022,10 +1020,12 @@
                bus_space_write_1(bst, bsh, PACKET_NUM_REG_B, packetno);
 
                /*
-                * Position the pointer to the beginning of the packet.
+                * Position the pointer to the beginning of the packet, wait
+                * for preload.
                 */
                bus_space_write_2(bst, bsh, POINTER_REG_W,
                    PTR_AUTOINC | PTR_READ /* | 0x0000 */);
+               delay(1);
 
                /*
                 * Fetch the TX status word.  This will be a copy of
@@ -1097,11 +1097,12 @@
                ifp->if_timer = 0;
        }
 
+       /*
+        * Internal PHY status change
+        */
        if (sc->sc_chipid == CHIP_91C111 && sc->sc_internal_phy &&
            (status & IM_MD_INT)) {
-               /*
-                * Internal PHY status change
-                */
+               smc91cxx_intr_ack_write(bst, bsh, IM_MD_INT);
                mii_tick(&sc->sc_mii);
        }
 
@@ -1160,6 +1161,7 @@
 
        bus_space_write_2(bst, bsh, POINTER_REG_W,
            PTR_READ | PTR_RCV | PTR_AUTOINC /* | 0x0000 */);
+       delay(1);
 
        /*
         * First two words are status and packet length.
@@ -1244,11 +1246,9 @@
                        *data = bus_space_read_1(bst, bsh, DATA_REG_B);
                }
        } else {
-               u_int8_t *dp;
-
                m->m_data = (void *) ALIGN(mtod(m, void *));
                eh = mtod(m, struct ether_header *);
-               dp = data = mtod(m, u_int8_t *);
+               data = mtod(m, u_int8_t *);
                KASSERT(trunc_page((uintptr_t)data) == 
trunc_page((uintptr_t)data + packetlen - 1));
                if (packetlen > 3)
                        bus_space_read_multi_stream_4(bst, bsh, DATA_REG_W,
@@ -1298,9 +1298,6 @@
        /*
         * Check for another packet.
         */
-       packetno = bus_space_read_2(bst, bsh, FIFO_PORTS_REG_W);
-       if (packetno & FIFO_REMPTY)
-               return;
        goto again;
 }