kern/41428: ath_cardbus does not setup latency timer

[kanaoka%ann.hi-ho.ne.jp@localhost]

>Number:         41428
>Category:       kern
>Synopsis:       ath_cardbus does not setup latency timer
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu May 14 14:30:00 +0000 2009
>Originator:     Masanori Kanaoka
>Release:        NetBSD-5.0RELEASE
>Organization:
>Environment:
NetBSD kana1.k.vnop.net 5.0 NetBSD 5.0 (KANA1-M2) #1: Tue May 12 23:20:40 JST 
2009  root%kana1.k.vnop.net@localhost:/usr/obj/sys/arch/i386/compile/KANA1-M2
>Description:
ath_pci_setup() set latency timer. but ath_cardbus_setup() does not.

>How-To-Repeat:
See ath_cardbus_setup and ath_pci_setup
>Fix:
Index: if_ath_cardbus.c
===================================================================
RCS file: /ftp/cvs/src/sys/dev/cardbus/if_ath_cardbus.c,v
retrieving revision 1.31
diff -u -r1.31 if_ath_cardbus.c
--- if_ath_cardbus.c    10 Jul 2008 05:11:10 -0000      1.31
+++ if_ath_cardbus.c    11 May 2009 14:31:28 -0000
@@ -267,7 +267,7 @@
        cardbus_chipset_tag_t cc = ct->ct_cc;
        cardbus_function_tag_t cf = ct->ct_cf;
        int rc;
-       pcireg_t reg;
+       pcireg_t reg,bhlc,icr,lattimer;
 
        if ((rc = cardbus_set_powerstate(ct, csc->sc_tag, PCI_PWR_D0)) != 0)
                aprint_debug("%s: cardbus_set_powerstate %d\n", __func__, rc);
@@ -280,4 +280,17 @@
            PCI_COMMAND_STATUS_REG);
        reg |= PCI_COMMAND_MASTER_ENABLE | PCI_COMMAND_MEM_ENABLE;
        cardbus_conf_write(cc, cf, csc->sc_tag, PCI_COMMAND_STATUS_REG, reg);
+
+       /*
+        * Make sure the latency timer is set to some reasonable
+        * value.
+        */
+       bhlc = cardbus_conf_read(cc, cf, csc->sc_tag, CARDBUS_BHLC_REG);
+       icr = cardbus_conf_read(cc, cf, csc->sc_tag, CARDBUS_INTERRUPT_REG);
+       lattimer = MAX(0x10, MIN(0xf8, 8 * PCI_MIN_GNT(icr)));
+       if (CARDBUS_LATTIMER(reg) < lattimer) {
+               bhlc &= ~(CARDBUS_LATTIMER_MASK << CARDBUS_LATTIMER_SHIFT);
+               bhlc |= (lattimer << CARDBUS_LATTIMER_SHIFT);
+               cardbus_conf_write(cc, cf, csc->sc_tag, CARDBUS_BHLC_REG, bhlc);
+       }
 }