[PATCH 13/13] sata_mv use hweight16() for bit counting (V2)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Some tidying as suggested by Grant Grundler.

Nuke local bit-counting function from sata_mv in favour of using hweight16().
Also add a short explanation for the 15msec timeout used when waiting for empty/idle.

Signed-off-by: Mark Lord <mlord@xxxxxxxxx>
---
Respin/repost of original patch 13: added #include <linux/bitops.h> for safety.

--- old/drivers/ata/sata_mv.c	2008-05-01 20:29:40.000000000 -0400
+++ linux/drivers/ata/sata_mv.c	2008-05-02 13:58:47.000000000 -0400
@@ -65,6 +65,7 @@
#include <linux/platform_device.h>
#include <linux/ata_platform.h>
#include <linux/mbus.h>
+#include <linux/bitops.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
@@ -903,6 +904,10 @@

	/*
	 * Wait for the EDMA engine to finish transactions in progress.
+	 * No idea what a good "timeout" value might be, but measurements
+	 * indicate that it often requires hundreds of microseconds
+	 * with two drives in-use.  So we use the 15msec value above
+	 * as a rough guess at what even more drives might require.
	 */
	for (i = 0; i < timeout; ++i) {
		u32 edma_stat = readl(port_mmio + EDMA_STATUS_OFS);
@@ -1640,17 +1645,6 @@
	return readl(port_mmio + SATA_TESTCTL_OFS) >> 16;
}

-static int mv_count_pmp_links(unsigned int pmp_map)
-{
-	unsigned int link_count = 0;
-
-	while (pmp_map) {
-		link_count += (pmp_map & 1);
-		pmp_map >>= 1;
-	}
-	return link_count;
-}
-
static void mv_pmp_eh_prep(struct ata_port *ap, unsigned int pmp_map)
{
	struct ata_eh_info *ehi;
@@ -1701,7 +1695,7 @@
		pp->delayed_eh_pmp_map = new_map;
		mv_pmp_eh_prep(ap, new_map & ~old_map);
	}
-	failed_links = mv_count_pmp_links(new_map);
+	failed_links = hweight16(new_map);

	ata_port_printk(ap, KERN_INFO, "%s: pmp_map=%04x qc_map=%04x "
			"failed_links=%d nr_active_links=%d\n",
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux