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ide-pmac: fix drive->init_speed reporting

PATCH In review Bartlomiej Zolnierkiewicz 3 participants 17 messages Jul 22, 2007 – Jul 29, 2007

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#0 lore raw

PATCH 1/1 ide-pmac: fix drive->init_speed reporting

pmac_ide_tune_chipset() don't set drive->init_speed.

Fix it by setting drive->{current,init}_speed in pmac_ide_do_setfeature() and clean up pmac_ide_{tune_chipset,mdma_enable,udma_enable}().

---
Goes before "[PATCH] ide-pmac: PIO mode setup fixes (take 2)" patch in the IDE quilt tree.

 drivers/ide/ppc/pmac.c |   14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)
drivers/ide/ppc/pmac.c +3 -11
Index: b/drivers/ide/ppc/pmac.c
===================================================================
@@ -602,6 +602,9 @@ out:
 				drive->id->dma_1word |= 0x0101; break;
 			default: break;
 		}
+		if (!drive->init_speed)
+			drive->init_speed = command;
+		drive->current_speed = command;
 	}
 	enable_irq(hwif->irq);
 	return result;
@@ -974,7 +977,6 @@ static int pmac_ide_tune_chipset(ide_dri
 		return ret;
 		
 	pmac_ide_do_update_timings(drive);	
-	drive->current_speed = speed;
 
 	return 0;
 }
@@ -1725,11 +1727,6 @@ pmac_ide_mdma_enable(ide_drive_t *drive,
 	/* Apply timings to controller */
 	*timings = timing_local[0];
 	*timings2 = timing_local[1];
-	
-	/* Set speed info in drive */
-	drive->current_speed = mode;	
-	if (!drive->init_speed)
-		drive->init_speed = mode;
 
 	return 1;
 }
@@ -1781,11 +1778,6 @@ pmac_ide_udma_enable(ide_drive_t *drive,
 	*timings = timing_local[0];
 	*timings2 = timing_local[1];
 
-	/* Set speed info in drive */
-	drive->current_speed = mode;	
-	if (!drive->init_speed)
-		drive->init_speed = mode;
-
 	return 1;
 }
 
Acked-by on v1 1/1
#1 lore raw
Quoted 5 lines · Bartlomiej Zolnierkiewicz

pmac_ide_tune_chipset() don't set drive->init_speed.

Fix it by setting drive->{current,init}_speed in pmac_ide_do_setfeature() and clean up pmac_ide_{tune_chipset,mdma_enable,udma_enable}().

Quoted 54 lines

---
Goes before "[PATCH] ide-pmac: PIO mode setup fixes (take 2)" patch in the IDE quilt tree.

 drivers/ide/ppc/pmac.c |   14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

Index: b/drivers/ide/ppc/pmac.c
===================================================================

drivers/ide/ppc/pmac.c +3 -11
@@ -602,6 +602,9 @@ out:
 				drive->id->dma_1word |= 0x0101; break;
 			default: break;
 		}
+		if (!drive->init_speed)
+			drive->init_speed = command;
+		drive->current_speed = command;
 	}
 	enable_irq(hwif->irq);
 	return result;
@@ -974,7 +977,6 @@ static int pmac_ide_tune_chipset(ide_dri
 		return ret;
 
 	pmac_ide_do_update_timings(drive);	
-	drive->current_speed = speed;
 
 	return 0;
 }
@@ -1725,11 +1727,6 @@ pmac_ide_mdma_enable(ide_drive_t *drive,
 	/* Apply timings to controller */
 	*timings = timing_local[0];
 	*timings2 = timing_local[1];
-	
-	/* Set speed info in drive */
-	drive->current_speed = mode;	
-	if (!drive->init_speed)
-		drive->init_speed = mode;
 
 	return 1;
 }
@@ -1781,11 +1778,6 @@ pmac_ide_udma_enable(ide_drive_t *drive,
 	*timings = timing_local[0];
 	*timings2 = timing_local[1];
 
-	/* Set speed info in drive */
-	drive->current_speed = mode;	
-	if (!drive->init_speed)
-		drive->init_speed = mode;
-
 	return 1;
 }
 
#2 lore raw
Quoted 8 lines · Benjamin Herrenschmidt
Quoted 5 lines · Bartlomiej Zolnierkiewicz

pmac_ide_tune_chipset() don't set drive->init_speed.

Fix it by setting drive->{current,init}_speed in pmac_ide_do_setfeature() and clean up pmac_ide_{tune_chipset,mdma_enable,udma_enable}().

added

#3 lore raw

ide patches

In reply to Bartlomiej Zolnierkiewicz

Note that with all your patches applied, it doesn't seem to auto-tune the speed at boot anymore and doesn't enable DMA. I can make it do so with hdparm -d1, in which case, for example, on this wallstreet, I get MDMA2 which is correct, however, it seems to also set PIO0 which it should set PIO4...

Ben.

#4 lore raw

Re: ide patches

Quoted 5 lines · Benjamin Herrenschmidt

Note that with all your patches applied, it doesn't seem to auto-tune the speed at boot anymore and doesn't enable DMA. I can make it do so with hdparm -d1, in which case, for example, on this wallstreet, I get MDMA2 which is correct, however, it seems to also set PIO0 which it should set PIO4...

One of the problems is that you do XFER_PIO + pio in pmac_ide_set_pio_mode(), which is no good. XFER_PIO is a bad constant name and causes that sort of confusion :-)

Fix is to use XFER_PIO_0 + pio. I'll send a patch fixing that plus a few other things on top of yours once I've found out what's up with DMA. I've enable autotune, I see it sending the 0x22 command, but hdparm still claims DMA isn't enabled.

Cheers,
Ben.

#5 lore raw

Re: ide patches

Quoted 7 lines · Benjamin Herrenschmidt
Quoted 5 lines · Benjamin Herrenschmidt

Note that with all your patches applied, it doesn't seem to auto-tune the speed at boot anymore and doesn't enable DMA. I can make it do so with hdparm -d1, in which case, for example, on this wallstreet, I get MDMA2 which is correct, however, it seems to also set PIO0 which it should set PIO4...

Quoted 8 lines

One of the problems is that you do XFER_PIO + pio in pmac_ide_set_pio_mode(), which is no good. XFER_PIO is a bad constant name and causes that sort of confusion :-)

Fix is to use XFER_PIO_0 + pio. I'll send a patch fixing that plus a few other things on top of yours once I've found out what's up with DMA. I've enable autotune, I see it sending the 0x22 command, but hdparm still claims DMA isn't enabled.

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel
to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think the whole idea of having a "current speed" is bogus here, we should have a separate current DMA speed and current PIO speed. We should be able to set the PIO timings without stopping DMA, toggling DMA is a separate affair.

- For some reason, nowadays, hdparm -p /dev/hda will not autotune, but
will set PIO 0 (hdparm -p 255 /dev/hda will autotune). Might be a bug in whatever hdparm version I have here.

- Some userland scripts installed on debian as part of the pbbuttonsd
package are doing hdaprm -p /dev/device on all IDE devices at boot.

I'm investigating what's broken with hdparm

Ben.

#6 lore raw

Re: ide patches

Quoted 12 lines

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel
to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think the whole idea of having a "current speed" is bogus here, we should have a separate current DMA speed and current PIO speed. We should be able to set the PIO timings without stopping DMA, toggling DMA is a separate affair.

Quoted 6 lines

- For some reason, nowadays, hdparm -p /dev/hda will not autotune, but
will set PIO 0 (hdparm -p 255 /dev/hda will autotune). Might be a bug in whatever hdparm version I have here.

- Some userland scripts installed on debian as part of the pbbuttonsd
package are doing hdaprm -p /dev/device on all IDE devices at boot.

In the meantime, that patch applied on top of your latest series fixes the PIO setting in the driver to send the correct mode value in pmac_ide_set_pio_mode(). I still object to your patch serie at this point because hdparm -p N should not, imho, cause DMA to be disabled.

I really believe that the kernel should keep track separately of PIO and DMA speeds.

drivers/ide/ppc/pmac.c +19 -9
Index: linux-work/drivers/ide/ppc/pmac.c
===================================================================
@@ -535,7 +535,7 @@ pmac_outbsync(ide_drive_t *drive, u8 val
 static void
 pmac_ide_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
-	u32 *timings;
+	u32 *timings, t;
 	unsigned accessTicks, recTicks;
 	unsigned accessTime, recTime;
 	pmac_ide_hwif_t* pmif = (pmac_ide_hwif_t *)HWIF(drive)->hwif_data;
@@ -546,6 +546,7 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 		
 	/* which drive is it ? */
 	timings = &pmif->timings[drive->select.b.unit & 0x01];
+	t = *timings;
 
 	cycle_time = ide_pio_cycle_time(drive, pio);
 
@@ -553,14 +554,14 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 	case controller_sh_ata6: {
 		/* 133Mhz cell */
 		u32 tr = kauai_lookup_timing(shasta_pio_timings, cycle_time);
-		*timings = ((*timings) & ~TR_133_PIOREG_PIO_MASK) | tr;
+		t = (t & ~TR_133_PIOREG_PIO_MASK) | tr;
 		break;
 		}
 	case controller_un_ata6:
 	case controller_k2_ata6: {
 		/* 100Mhz cell */
 		u32 tr = kauai_lookup_timing(kauai_pio_timings, cycle_time);
-		*timings = ((*timings) & ~TR_100_PIOREG_PIO_MASK) | tr;
+		t = (t & ~TR_100_PIOREG_PIO_MASK) | tr;
 		break;
 		}
 	case controller_kl_ata4:
@@ -574,9 +575,9 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 		accessTicks = min(accessTicks, 0x1fU);
 		recTicks = SYSCLK_TICKS_66(recTime);
 		recTicks = min(recTicks, 0x1fU);
-		*timings = ((*timings) & ~TR_66_PIO_MASK) |
-				(accessTicks << TR_66_PIO_ACCESS_SHIFT) |
-				(recTicks << TR_66_PIO_RECOVERY_SHIFT);
+		t = (t & ~TR_66_PIO_MASK) |
+			(accessTicks << TR_66_PIO_ACCESS_SHIFT) |
+			(recTicks << TR_66_PIO_RECOVERY_SHIFT);
 		break;
 	default: {
 		/* 33Mhz cell */
@@ -596,11 +597,11 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 			recTicks--; /* guess, but it's only for PIO0, so... */
 			ebit = 1;
 		}
-		*timings = ((*timings) & ~TR_33_PIO_MASK) |
+		t = (t & ~TR_33_PIO_MASK) |
 				(accessTicks << TR_33_PIO_ACCESS_SHIFT) |
 				(recTicks << TR_33_PIO_RECOVERY_SHIFT);
 		if (ebit)
-			*timings |= TR_33_PIO_E;
+			t |= TR_33_PIO_E;
 		break;
 		}
 	}
@@ -610,9 +611,10 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 		drive->name, pio,  *timings);
 #endif	
 
-	if (ide_config_drive_speed(drive, XFER_PIO + pio))
+	if (ide_config_drive_speed(drive, XFER_PIO_0 + pio))
 		return;
 
+	*timings = t;
 	pmac_ide_do_update_timings(drive);
 }
 
@@ -1150,6 +1152,8 @@ pmac_ide_setup_device(pmac_ide_hwif_t *p
 	hwif->cbl = pmif->cable_80 ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 	hwif->drives[0].unmask = 1;
 	hwif->drives[1].unmask = 1;
+	hwif->drives[0].autotune = IDE_TUNE_AUTO;
+	hwif->drives[1].autotune = IDE_TUNE_AUTO;
 	hwif->pio_mask = ATA_PIO4;
 	hwif->set_pio_mode = pmac_ide_set_pio_mode;
 	if (pmif->kind == controller_un_ata6
@@ -1766,10 +1770,16 @@ pmac_ide_dma_test_irq (ide_drive_t *driv
 
 static void pmac_ide_dma_host_off(ide_drive_t *drive)
 {
+#ifdef IDE_PMAC_DEBUG
+	printk(KERN_ERR "%s: dma_host_off()\n", drive->name);
+#endif
 }
 
 static void pmac_ide_dma_host_on(ide_drive_t *drive)
 {
+#ifdef IDE_PMAC_DEBUG
+	printk(KERN_ERR "%s: dma_host_on()\n", drive->name);
+#endif
 }
 
 static void
#7 lore raw

Re: ide patches

Hello.

Quoted 7 lines · Benjamin Herrenschmidt

In the meantime, that patch applied on top of your latest series fixes the PIO setting in the driver to send the correct mode value in pmac_ide_set_pio_mode(). I still object to your patch serie at this point because hdparm -p N should not, imho, cause DMA to be disabled.

I really believe that the kernel should keep track separately of PIO and DMA speeds.

We do too. :-)

Quoted 5 lines

Index: linux-work/drivers/ide/ppc/pmac.c
===================================================================

drivers/ide/ppc/pmac.c +0 -0
@@ -535,7 +535,7 @@ pmac_outbsync(ide_drive_t *drive, u8 val

[...]

drivers/ide/ppc/pmac.c pmac_ide_setup_device(pmac_ide_hwif_t *p · line 1156

Quoted 6 lines
drivers/ide/ppc/pmac.c +2 -0
@@ -1150,6 +1152,8 @@ pmac_ide_setup_device(pmac_ide_hwif_t *p
 	hwif->cbl = pmif->cable_80 ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 	hwif->drives[0].unmask = 1;
 	hwif->drives[1].unmask = 1;
+	hwif->drives[0].autotune = IDE_TUNE_AUTO;
+	hwif->drives[1].autotune = IDE_TUNE_AUTO;

Hm, indeed, most of the other drivers are just using 1.

Quoted 8 lines
drivers/ide/ppc/pmac.c +1 -0
 	hwif->pio_mask = ATA_PIO4;
 	hwif->set_pio_mode = pmac_ide_set_pio_mode;
 	if (pmif->kind == controller_un_ata6
@@ -1766,10 +1770,16 @@ pmac_ide_dma_test_irq (ide_drive_t *driv
 
 static void pmac_ide_dma_host_off(ide_drive_t *drive)
 {
+#ifdef IDE_PMAC_DEBUG

drivers/ide/ppc/pmac.c pmac_ide_dma_test_irq (ide_drive_t *driv · line 1783

Quoted 10 lines
drivers/ide/ppc/pmac.c +5 -0
+	printk(KERN_ERR "%s: dma_host_off()\n", drive->name);
+#endif
 }
 
 static void pmac_ide_dma_host_on(ide_drive_t *drive)
 {
+#ifdef IDE_PMAC_DEBUG
+	printk(KERN_ERR "%s: dma_host_on()\n", drive->name);
+#endif
 }

Gah! Why the debug messages might be using KERN_ERR?

MBR, Sergei

#8 lore raw

Re: ide patches

Quoted 2 lines

Gah! Why the debug messages might be using KERN_ERR?

Blah, other debug messages where like that and I copy/pasted stupidly. I suppose at one point, somebody (maybe me) decided that it was a PITA to have to add "debug" on the kernel command line :-)

I will change all of these to pr_debug anyway.

Cheers,
Ben.

#9 lore raw

Re: ide patches

In reply to Benjamin Herrenschmidt

Hi,

Thanks for reviewing and testing this patch series.

Quoted 7 lines · Benjamin Herrenschmidt
Quoted 7 lines

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel
to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think

The problem is that _many_ chipsets don't support separate PIO and DMA timings so disabling DMA while programming chipset for PIO timings is a necessity for them.

Quoted 8 lines
Quoted 8 lines

the whole idea of having a "current speed" is bogus here, we should have a separate current DMA speed and current PIO speed. We should be able to set the PIO timings without stopping DMA, toggling DMA is a separate affair.

- For some reason, nowadays, hdparm -p /dev/hda will not autotune, but
will set PIO 0 (hdparm -p 255 /dev/hda will autotune). Might be a bug in whatever hdparm version I have here.

Since -p 255 works fine it would indicate a hdparm issue.

Quoted 5 lines
Quoted 2 lines

- Some userland scripts installed on debian as part of the pbbuttonsd
package are doing hdaprm -p /dev/device on all IDE devices at boot.

In the meantime, that patch applied on top of your latest series fixes the PIO setting in the driver to send the correct mode value in

Looks fine.

Could you please rebase it on top of the fixed "ide-pmac: PIO mode setup fixes" patch, remove debugging printks and add description/Signed-off-by?

Also since the patch series has been tested please verify that your concerns wrt patches #4, #8 and #10 are still valid.

Quoted 2 lines

pmac_ide_set_pio_mode(). I still object to your patch serie at this point because hdparm -p N should not, imho, cause DMA to be disabled.

If this change indeed causes some serious problem which breaks userland on ppc (that can't be workarounded otherwise) we may add a new ->host_flags flag and special hack to ide-io.c::do_special(), something like:

...

		int keep_dma = drive->using_dma;
...
			ide_set_pio(drive, req_pio);
...
		if (hwif->host_flags & IDE_HFLAG_SET_PIO_MODE_KEEP_DMA) {
			if (keep_dma)
				hwif->ide_dma_on(drive);
		}

...

which should preserve the old behavior.

I will respin patch #11 with necessary changes if needed.

Quoted 2 lines

I really believe that the kernel should keep track separately of PIO and DMA speeds.

Agreed.

Thanks,
Bart

Quoted 103 lines

Index: linux-work/drivers/ide/ppc/pmac.c
===================================================================

drivers/ide/ppc/pmac.c +19 -9
@@ -535,7 +535,7 @@ pmac_outbsync(ide_drive_t *drive, u8 val
 static void
 pmac_ide_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
-	u32 *timings;
+	u32 *timings, t;
 	unsigned accessTicks, recTicks;
 	unsigned accessTime, recTime;
 	pmac_ide_hwif_t* pmif = (pmac_ide_hwif_t *)HWIF(drive)->hwif_data;
@@ -546,6 +546,7 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 
 	/* which drive is it ? */
 	timings = &pmif->timings[drive->select.b.unit & 0x01];
+	t = *timings;
 
 	cycle_time = ide_pio_cycle_time(drive, pio);
 
@@ -553,14 +554,14 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 	case controller_sh_ata6: {
 		/* 133Mhz cell */
 		u32 tr = kauai_lookup_timing(shasta_pio_timings, cycle_time);
-		*timings = ((*timings) & ~TR_133_PIOREG_PIO_MASK) | tr;
+		t = (t & ~TR_133_PIOREG_PIO_MASK) | tr;
 		break;
 		}
 	case controller_un_ata6:
 	case controller_k2_ata6: {
 		/* 100Mhz cell */
 		u32 tr = kauai_lookup_timing(kauai_pio_timings, cycle_time);
-		*timings = ((*timings) & ~TR_100_PIOREG_PIO_MASK) | tr;
+		t = (t & ~TR_100_PIOREG_PIO_MASK) | tr;
 		break;
 		}
 	case controller_kl_ata4:
@@ -574,9 +575,9 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 		accessTicks = min(accessTicks, 0x1fU);
 		recTicks = SYSCLK_TICKS_66(recTime);
 		recTicks = min(recTicks, 0x1fU);
-		*timings = ((*timings) & ~TR_66_PIO_MASK) |
-				(accessTicks << TR_66_PIO_ACCESS_SHIFT) |
-				(recTicks << TR_66_PIO_RECOVERY_SHIFT);
+		t = (t & ~TR_66_PIO_MASK) |
+			(accessTicks << TR_66_PIO_ACCESS_SHIFT) |
+			(recTicks << TR_66_PIO_RECOVERY_SHIFT);
 		break;
 	default: {
 		/* 33Mhz cell */
@@ -596,11 +597,11 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 			recTicks--; /* guess, but it's only for PIO0, so... */
 			ebit = 1;
 		}
-		*timings = ((*timings) & ~TR_33_PIO_MASK) |
+		t = (t & ~TR_33_PIO_MASK) |
 				(accessTicks << TR_33_PIO_ACCESS_SHIFT) |
 				(recTicks << TR_33_PIO_RECOVERY_SHIFT);
 		if (ebit)
-			*timings |= TR_33_PIO_E;
+			t |= TR_33_PIO_E;
 		break;
 		}
 	}
@@ -610,9 +611,10 @@ pmac_ide_set_pio_mode(ide_drive_t *drive
 		drive->name, pio,  *timings);
 #endif	
 
-	if (ide_config_drive_speed(drive, XFER_PIO + pio))
+	if (ide_config_drive_speed(drive, XFER_PIO_0 + pio))
 		return;
 
+	*timings = t;
 	pmac_ide_do_update_timings(drive);
 }
 
@@ -1150,6 +1152,8 @@ pmac_ide_setup_device(pmac_ide_hwif_t *p
 	hwif->cbl = pmif->cable_80 ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 	hwif->drives[0].unmask = 1;
 	hwif->drives[1].unmask = 1;
+	hwif->drives[0].autotune = IDE_TUNE_AUTO;
+	hwif->drives[1].autotune = IDE_TUNE_AUTO;
 	hwif->pio_mask = ATA_PIO4;
 	hwif->set_pio_mode = pmac_ide_set_pio_mode;
 	if (pmif->kind == controller_un_ata6
@@ -1766,10 +1770,16 @@ pmac_ide_dma_test_irq (ide_drive_t *driv
 
 static void pmac_ide_dma_host_off(ide_drive_t *drive)
 {
+#ifdef IDE_PMAC_DEBUG
+	printk(KERN_ERR "%s: dma_host_off()\n", drive->name);
+#endif
 }
 
 static void pmac_ide_dma_host_on(ide_drive_t *drive)
 {
+#ifdef IDE_PMAC_DEBUG
+	printk(KERN_ERR "%s: dma_host_on()\n", drive->name);
+#endif
 }
 
 static void
#10 lore raw

Re: ide patches

Quoted 8 lines · Bartlomiej Zolnierkiewicz

Hi,

Thanks for reviewing and testing this patch series.

Quoted 3 lines · Benjamin Herrenschmidt
Quoted 3 lines

Ok, there's a combination of things here:

Quoted 8 lines
Quoted 4 lines
Quoted 4 lines

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel
to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think

The problem is that _many_ chipsets don't support separate PIO and DMA timings so disabling DMA while programming chipset for PIO timings is a necessity for them.

Disabling while programming is fine with me. The problem is that we don't restore DMA after programming the PIO timings.

Yes, but we still need to address it as it's a regression for ide-pmac when moving to the generic ide_config_drive_speed.

Quoted 5 lines
Quoted 3 lines
Quoted 3 lines

- For some reason, nowadays, hdparm -p /dev/hda will not autotune, but
will set PIO 0 (hdparm -p 255 /dev/hda will autotune). Might be a bug in whatever hdparm version I have here.

Since -p 255 works fine it would indicate a hdparm issue.

Yup. All hdparm's around do that, I need to find out when it actually broke (if it did, but I -think- that early versions used to autotune with just -p).

Quoted 10 lines
Quoted 5 lines
Quoted 2 lines

- Some userland scripts installed on debian as part of the pbbuttonsd
package are doing hdaprm -p /dev/device on all IDE devices at boot.

In the meantime, that patch applied on top of your latest series fixes the PIO setting in the driver to send the correct mode value in

Looks fine.

Could you please rebase it on top of the fixed "ide-pmac: PIO mode setup fixes" patch, remove debugging printks and add description/Signed-off-by?

Sure.

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Also since the patch series has been tested please verify that your concerns wrt patches #4, #8 and #10 are still valid.

I've been using that weird machine without problems at boot, but I still need to test actual hotplug of the media bay, this is usually when the shit hits the fan. It's quite possible that some of the fixes you did to ide_config_drive_speed() (or other changes around) are also fixing that problem, it used to look a lot like a heisenbug back then. However, I'm still annoyed that with all current debian or ubuntu distro, you'll end up with DMA disabled at boot because of those pbbuttons scripts.

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pmac_ide_set_pio_mode(). I still object to your patch serie at this point because hdparm -p N should not, imho, cause DMA to be disabled.

If this change indeed causes some serious problem which breaks userland on ppc (that can't be workarounded otherwise) we may add a new ->host_flags flag and special hack to ide-io.c::do_special(), something like:

...

		int keep_dma = drive->using_dma;
...
			ide_set_pio(drive, req_pio);
...
		if (hwif->host_flags & IDE_HFLAG_SET_PIO_MODE_KEEP_DMA) {
			if (keep_dma)
				hwif->ide_dma_on(drive);
		}
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...

which should preserve the old behavior.

Yea, please.

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I will respin patch #11 with necessary changes if needed.

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I really believe that the kernel should keep track separately of PIO and DMA speeds.

Agreed.

Excellent, we all agree :-)

Cheers,
Ben.

#11 lore raw

Re: ide patches

In reply to Bartlomiej Zolnierkiewicz
Quoted 10 lines · Bartlomiej Zolnierkiewicz
Quoted 6 lines
Quoted 6 lines

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think

The problem is that _many_ chipsets don't support separate PIO and DMA timings so disabling DMA while programming chipset for PIO timings is a necessity for them.

Actually, I didn't quite follow (as I'm afraid Ben also :-). Do you mean
the fact that the DMA timings may get overwritten (which happens due to the failure of the drivers to handle the shared PIO/DMA timing registers, and in some cases by "coupling" PIO to UltraDMA timings for no apparent reasons which leads to disabling UltraDMA when PIO is being programmed)?

MBR, Sergei

#12 lore raw

Re: ide patches

Quoted 13 lines · Sergei Shtylyov
Quoted 10 lines · Bartlomiej Zolnierkiewicz
Quoted 6 lines
Quoted 6 lines

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think

The problem is that _many_ chipsets don't support separate PIO and DMA timings so disabling DMA while programming chipset for PIO timings is a necessity for them.

Quoted 5 lines

Actually, I didn't quite follow (as I'm afraid Ben also :-). Do you mean
the fact that the DMA timings may get overwritten (which happens due to the failure of the drivers to handle the shared PIO/DMA timing registers, and in some cases by "coupling" PIO to UltraDMA timings for no apparent reasons which leads to disabling UltraDMA when PIO is being programmed)?

Yes, in particular I meant cases like cmd64x (shared MWDMA/PIO timing registers) so doing "hdparm -p" on a drive currently using DMA without ide_config_drive_speed() disabling DMA would result in DMA operations using PIO timings and possible data corruptions.

BTW all PIO to (U)DMA "couplings" should be fixed now

Bart

#13 lore raw

Re: ide patches

In reply to Benjamin Herrenschmidt

Hello.

Quoted 9 lines · Benjamin Herrenschmidt
Quoted 9 lines
Quoted 5 lines

Note that with all your patches applied, it doesn't seem to auto-tune the speed at boot anymore and doesn't enable DMA. I can make it do so with hdparm -d1, in which case, for example, on this wallstreet, I get MDMA2 which is correct, however, it seems to also set PIO0 which it should set PIO4...

One of the problems is that you do XFER_PIO + pio in pmac_ide_set_pio_mode(), which is no good. XFER_PIO is a bad constant name and causes that sort of confusion :-)

Yeah, it's #define'd as 0 in drivers/ide/ide-timings.h... :-/

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Fix is to use XFER_PIO_0 + pio. I'll send a patch fixing that plus a few

I think Bart will just recast his patch (as usual).

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other things on top of yours once I've found out what's up with DMA. I've enable autotune, I see it sending the 0x22 command, but hdparm still claims DMA isn't enabled.

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel
to disable DMA, which I think is incorrect.

That's the way ide_config_drive_speed() works.

Quoted 1 line

It's not the case with 2.6.22 from my quick tests.

Which means that PIO autotuning is broken there, i.e. that
ide_config_drive_speed() not called from the driver's tuneproc() method.

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The problem is that ide_config_drive_speed
disables DMA, but only re-enables it when setting a DMA speed.

It never "re-enables" DMA. ide_dma_host_on() method is not the same as
ide_dma_on() which actually enables DMA.

Quoted 5 lines

I think
the whole idea of having a "current speed" is bogus here, we should have a separate current DMA speed and current PIO speed. We should be able to set the PIO timings without stopping DMA, toggling DMA is a separate affair.

Agreed completely.

MBR, Sergei

#14 lore raw

Re: ide patches

Quoted 6 lines
Quoted 4 lines

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel
to disable DMA, which I think is incorrect.

That's the way ide_config_drive_speed() works.

And I still think that's bad.

Quoted 4 lines
Quoted 1 line

It's not the case with 2.6.22 from my quick tests.

Which means that PIO autotuning is broken there, i.e. that
ide_config_drive_speed() not called from the driver's tuneproc() method.

Yes, the driver uses it's own function which doesn't disable DMA permanently, which is, IMHO, the way to go. I consider the current behaviour a regression.

Quoted 5 lines
Quoted 2 lines

The problem is that ide_config_drive_speed
disables DMA, but only re-enables it when setting a DMA speed.

It never "re-enables" DMA. ide_dma_host_on() method is not the same as
ide_dma_on() which actually enables DMA.

Ugh ? It re-enables DMA in the sense that if called to configure a DMA speed, it re-enables dma on the host, thus effectively leaving with DMA enabled.

Quoted 7 lines
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I think
the whole idea of having a "current speed" is bogus here, we should have a separate current DMA speed and current PIO speed. We should be able to set the PIO timings without stopping DMA, toggling DMA is a separate affair.

Agreed completely.

Ah good :-)

Cheers,
Ben.

#15 lore raw

Re: ide patches

Hello.

Quoted 8 lines · Benjamin Herrenschmidt
Quoted 6 lines
Quoted 4 lines

Ok, there's a combination of things here:

- First, doing a set_pio from userland (hdparm -p XX) causes the kernel to disable DMA, which I think is incorrect.

That's the way ide_config_drive_speed() works.

And I still think that's bad.

Bart has just named one reason for that -- many chips have shared PIO/DMA
timing regs -- not all driver actually care about that issue and that's *not* the safest way to do this via ide_dma_{on|off}() calls anyway...

Quoted 8 lines
Quoted 4 lines
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It's not the case with 2.6.22 from my quick tests.

Which means that PIO autotuning is broken there, i.e. that
ide_config_drive_speed() not called from the driver's tuneproc() method.

Yes, the driver uses it's own function which doesn't disable DMA permanently, which is, IMHO, the way to go. I consider the current behaviour a regression.

Hm... "it's the way the cookie crumbles" for all the other drivers. :-)

Quoted 9 lines
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The problem is that ide_config_drive_speed
disables DMA, but only re-enables it when setting a DMA speed.

It never "re-enables" DMA. ide_dma_host_on() method is not the same as
ide_dma_on() which actually enables DMA.

Ugh ? It re-enables DMA in the sense that if called to configure a DMA speed, it re-enables dma on the host, thus effectively leaving with DMA enabled.

No. DMA is still diabled for the IDE core at this point. You need a real
ide_dma_on() method call to do it.

MBR, Sergei

#16 lore raw

Re: ide patches

Quoted 9 lines · Sergei Shtylyov
Quoted 1 line

Ugh ? It re-enables DMA in the sense that if called to configure a

DMA

Quoted 1 line

speed, it re-enables dma on the host, thus effectively leaving with

DMA

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enabled.

No. DMA is still diabled for the IDE core at this point. You need
a real
ide_dma_on() method call to do it.

Ah right... even worse :-)

Ben.