IB/ipath: Enable 4KB MTU

[net-next-2.6.git] / drivers / infiniband / hw / ipath / ipath_init_chip.c

diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 5428affa9102847d331c0f56cd72eb18844cb079..f0d7848d9bb1adffdc2625146fa4b5d6e7d6e40b 100644 (file)
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -155,24 +155,13 @@ static int bringup_link(struct ipath_devdata *dd)
                         dd->ipath_control);
 
        /*
-        * Note that prior to try 14 or 15 of IB, the credit scaling
-        * wasn't working, because it was swapped for writes with the
-        * 1 bit default linkstate field
+        * set initial max size pkt IBC will send, including ICRC; it's the
+        * PIO buffer size in dwords, less 1; also see ipath_set_mtu()
         */
+       val = (dd->ipath_ibmaxlen >> 2) + 1;
+       ibc = val << dd->ibcc_mpl_shift;
 
-       /* ignore pbc and align word */
-       val = dd->ipath_piosize2k - 2 * sizeof(u32);
-       /*
-        * for ICRC, which we only send in diag test pkt mode, and we
-        * don't need to worry about that for mtu
-        */
-       val += 1;
-       /*
-        * Set the IBC maxpktlength to the size of our pio buffers the
-        * maxpktlength is in words.  This is *not* the IB data MTU.
-        */
-       ibc = (val / sizeof(u32)) << INFINIPATH_IBCC_MAXPKTLEN_SHIFT;
-       /* in KB */
+       /* flowcontrolwatermark is in units of KBytes */
        ibc |= 0x5ULL << INFINIPATH_IBCC_FLOWCTRLWATERMARK_SHIFT;
        /*
         * How often flowctrl sent.  More or less in usecs; balance against
@@ -295,12 +284,9 @@ static int init_chip_first(struct ipath_devdata *dd,
        val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_sendpiosize);
        dd->ipath_piosize2k = val & ~0U;
        dd->ipath_piosize4k = val >> 32;
-       /*
-        * Note: the chips support a maximum MTU of 4096, but the driver
-        * hasn't implemented this feature yet, so set the initial value
-        * to 2048.
-        */
-       dd->ipath_ibmtu = 2048;
+       if (dd->ipath_piosize4k == 0 && ipath_mtu4096)
+               ipath_mtu4096 = 0; /* 4KB not supported by this chip */
+       dd->ipath_ibmtu = ipath_mtu4096 ? 4096 : 2048;
        val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_sendpiobufcnt);
        dd->ipath_piobcnt2k = val & ~0U;
        dd->ipath_piobcnt4k = val >> 32;