svn commit: r234304 - head/sys/dev/ath

[Adrian Chadd]

Author: adrian
Date: Sun Apr 15 00:04:23 2012
New Revision: 234304
URL: http://svn.freebsd.org/changeset/base/234304

Log:
  Override some default values to work around various issues in the deep,
  dirty and murky past.
  
  * Override the default cache line size to be something reasonable if
    it's set to 0.  Some NICs initialise with '0' (eg embedded ones)
    and there are comments in the driver stating that various OSes (eg
    older Linux ones) would incorrectly program things and 0 out this
    register.
  
  * Just default to overriding the latency timer.  Every other driver
    does this.
  
  * Use a default cache line size of 32 bytes.  It should be "reasonable
    enough".
  
  Obtained from:	Linux ath9k, Atheros

Modified:
  head/sys/dev/ath/if_ath_pci.c

Modified: head/sys/dev/ath/if_ath_pci.c
==============================================================================
--- head/sys/dev/ath/if_ath_pci.c	Sat Apr 14 23:59:58 2012	(r234303)
+++ head/sys/dev/ath/if_ath_pci.c	Sun Apr 15 00:04:23 2012	(r234304)
@@ -82,13 +82,27 @@ struct ath_pci_softc {
 #define	PCIR_RETRY_TIMEOUT	0x41
 #define	PCIR_CFG_PMCSR		0x48
 
+#define	DEFAULT_CACHESIZE	32
+
 static void
 ath_pci_setup(device_t dev)
 {
-#ifdef	ATH_PCI_LATENCY_WAR
+	uint8_t cz;
+
+	/* XXX TODO: need to override the _system_ saved copies of this */
+
+	/*
+	 * If the cache line size is 0, force it to a reasonable
+	 * value.
+	 */
+	cz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
+	if (cz == 0) {
+		pci_write_config(dev, PCIR_CACHELNSZ,
+		    DEFAULT_CACHESIZE / 4, 1);
+	}
+
 	/* Override the system latency timer */
-	pci_write_config(dev, PCIR_LATTIMER, 0x80, 1);
-#endif
+	pci_write_config(dev, PCIR_LATTIMER, 0xa8, 1);
 
 	/* If a PCI NIC, force wakeup */
 #ifdef	ATH_PCI_WAKEUP_WAR