ide: remove PIO "downgrade" quirk

No need for it nowadays so remove quirk code from ide_get_best_pio_mode()
and IDE_HFLAG_PIO_DOWNGRADE host flag.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 7031a8d..fa4c194 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -274,16 +274,6 @@
 		if (overridden)
 			printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
 					 drive->name);
-
-		/*
-		 * Conservative "downgrade" for all pre-ATA2 drives
-		 */
-		if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_DOWNGRADE) == 0 &&
-		    pio_mode && pio_mode < 4) {
-			pio_mode--;
-			printk(KERN_INFO "%s: applying conservative "
-					 "PIO \"downgrade\"\n", drive->name);
-		}
 	}
 
 	if (pio_mode > max_mode)
diff --git a/drivers/ide/pci/amd74xx.c b/drivers/ide/pci/amd74xx.c
index 6851726..ff684d3 100644
--- a/drivers/ide/pci/amd74xx.c
+++ b/drivers/ide/pci/amd74xx.c
@@ -219,7 +219,6 @@
 
 #define IDE_HFLAGS_AMD \
 	(IDE_HFLAG_PIO_NO_BLACKLIST | \
-	 IDE_HFLAG_PIO_NO_DOWNGRADE | \
 	 IDE_HFLAG_ABUSE_SET_DMA_MODE | \
 	 IDE_HFLAG_POST_SET_MODE | \
 	 IDE_HFLAG_IO_32BIT | \
diff --git a/drivers/ide/pci/via82cxxx.c b/drivers/ide/pci/via82cxxx.c
index b55d2e4..cff3caf 100644
--- a/drivers/ide/pci/via82cxxx.c
+++ b/drivers/ide/pci/via82cxxx.c
@@ -429,7 +429,6 @@
 	.init_hwif	= init_hwif_via82cxxx,
 	.enablebits	= { { 0x40, 0x02, 0x02 }, { 0x40, 0x01, 0x01 } },
 	.host_flags	= IDE_HFLAG_PIO_NO_BLACKLIST |
-			  IDE_HFLAG_PIO_NO_DOWNGRADE |
 			  IDE_HFLAG_ABUSE_SET_DMA_MODE |
 			  IDE_HFLAG_POST_SET_MODE |
 			  IDE_HFLAG_IO_32BIT,
diff --git a/drivers/ide/ppc/pmac.c b/drivers/ide/ppc/pmac.c
index 8f4080c..177961e 100644
--- a/drivers/ide/ppc/pmac.c
+++ b/drivers/ide/ppc/pmac.c
@@ -921,7 +921,6 @@
 static const struct ide_port_info pmac_port_info = {
 	.chipset		= ide_pmac,
 	.host_flags		= IDE_HFLAG_SET_PIO_MODE_KEEP_DMA |
-				  IDE_HFLAG_PIO_NO_DOWNGRADE |
 				  IDE_HFLAG_POST_SET_MODE |
 				  IDE_HFLAG_NO_DMA | /* no SFF-style DMA */
 				  IDE_HFLAG_UNMASK_IRQS,
diff --git a/include/linux/ide.h b/include/linux/ide.h
index eccc42b..c6d4de6 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1027,8 +1027,6 @@
 	IDE_HFLAG_SINGLE		= (1 << 1),
 	/* don't use legacy PIO blacklist */
 	IDE_HFLAG_PIO_NO_BLACKLIST	= (1 << 2),
-	/* don't use conservative PIO "downgrade" */
-	IDE_HFLAG_PIO_NO_DOWNGRADE	= (1 << 3),
 	/* use PIO8/9 for prefetch off/on */
 	IDE_HFLAG_ABUSE_PREFETCH	= (1 << 4),
 	/* use PIO6/7 for fast-devsel off/on */