Re: 40-wire cable detected when directly connected

["Tobias Müller" <Tobias_Mueller@twam.info>]

[-- Attachment #1.1: Type: text/plain, Size: 3210 bytes --]

Hi

Bartlomiej Zolnierkiewicz schrieb:
> As a workaround you can try using IDE subsystem siimage driver and pass
> "idex=ata66" option or modify Tejun's patch to also override device side
> cable detection by replacing ATA_CBL_PATA80 with ATA_CBL_PATA40_SHORT.
I changed some code in libata=core.c in ata_dev_xfermask (see patch2), 
that xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA) isn't set, when forcing 80c.

Everything seems to work now. I have a about 41 MB/s while reading.

Regards
   Tobias


dmesg says

[   40.854101] ata7: PATA max UDMA/133 irq 16
[   40.854162] ata8: PATA max UDMA/133 irq 16
[   41.008881] ata7: forcing 80c
[   41.008949] ata7.00: ATA-4: SanDisk SDCFX4-8192, HDX 4.20, max UDMA/66
[   41.009014] ata7.00: 16007040 sectors, multi 0: LBA
[   41.009751] ata7.00: configured for UDMA/66
[   41.168606] ata8: forcing 80c
[   41.168673] ata8.00: ATA-4: SanDisk SDCFX3-2048, HDX 4.08, max MWDMA2
[   41.168738] ata8.00: 4001760 sectors, multi 0: LBA
[   41.188267] ata8.00: configured for MWDMA2
[   41.188418] scsi 6:0:0:0: Direct-Access     ATA      SanDisk SDCFX4-8 
HDX  PQ: 0 ANSI: 5
[   41.188622] sd 6:0:0:0: [sdc] 16007040 512-byte hardware sectors 
(8196 MB)
[   41.188696] sd 6:0:0:0: [sdc] Write Protect is off
[   41.188759] sd 6:0:0:0: [sdc] Mode Sense: 00 3a 00 00
[   41.188776] sd 6:0:0:0: [sdc] Write cache: disabled, read cache: 
enabled, doesn't support DPO or FUA
[   41.188918] sd 6:0:0:0: [sdc] 16007040 512-byte hardware sectors 
(8196 MB)
[   41.188990] sd 6:0:0:0: [sdc] Write Protect is off
[   41.189054] sd 6:0:0:0: [sdc] Mode Sense: 00 3a 00 00
[   41.189070] sd 6:0:0:0: [sdc] Write cache: disabled, read cache: 
enabled, doesn't support DPO or FUA
[   41.189167]  sdc: sdc1 sdc2
[   41.189880] sd 6:0:0:0: [sdc] Attached SCSI disk
[   41.190092] scsi 7:0:0:0: Direct-Access     ATA      SanDisk SDCFX3-2 
HDX  PQ: 0 ANSI: 5
[   41.190283] sd 7:0:0:0: [sdd] 4001760 512-byte hardware sectors (2049 MB)
[   41.190357] sd 7:0:0:0: [sdd] Write Protect is off
[   41.190419] sd 7:0:0:0: [sdd] Mode Sense: 00 3a 00 00
[   41.190436] sd 7:0:0:0: [sdd] Write cache: disabled, read cache: 
enabled, doesn't support DPO or FUA
[   41.190567] sd 7:0:0:0: [sdd] 4001760 512-byte hardware sectors (2049 MB)
[   41.190640] sd 7:0:0:0: [sdd] Write Protect is off
[   41.190702] sd 7:0:0:0: [sdd] Mode Sense: 00 3a 00 00
[   41.190719] sd 7:0:0:0: [sdd] Write cache: disabled, read cache: 
enabled, doesn't support DPO or FUA
[   41.190815]  sdd: sdd1
[   41.191733] sd 7:0:0:0: [sdd] Attached SCSI disk


hdparm -I /dev/sda

[...]
Capabilities:
         LBA, IORDY(may be)(cannot be disabled)
         Standby timer values: spec'd by Vendor
         R/W multiple sector transfer: Max = 4   Current = 0
         DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 *udma4
              Cycle time: min=120ns recommended=120ns
         PIO: pio0 pio1 pio2 pio3 pio4
              Cycle time: no flow control=120ns  IORDY flow control=120ns
[...]



dd if=/dev/sdc of=/dev/null bs=1M count=16 iflag=direct

16+0 Datensätze ein
16+0 Datensätze aus
16777216 Bytes (17 MB) kopiert, 0,402367 s, 41,7 MB/s


[-- Attachment #1.2: patch2 --]
[-- Type: text/plain, Size: 3893 bytes --]

diff --git a/linux-2.6.24-rc7/drivers/ata/libata-core.c b/linux-2.6.24-rc7-twam/drivers/ata/libata-core.c
index 4753a18..ac5a0d4 100644
--- a/linux-2.6.24-rc7/drivers/ata/libata-core.c
+++ b/linux-2.6.24-rc7-twam/drivers/ata/libata-core.c
@@ -119,6 +119,10 @@ int libata_noacpi = 0;
 module_param_named(noacpi, libata_noacpi, int, 0444);
 MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set");
 
+int libata_force_cbl = 0;
+module_param_named(force_cbl, libata_force_cbl, int, 0644);
+MODULE_PARM_DESC(force_cbl, "force PATA cable type (0=keep, 40=40c, 80=80c)");
+
 MODULE_AUTHOR("Jeff Garzik");
 MODULE_DESCRIPTION("Library module for ATA devices");
 MODULE_LICENSE("GPL");
@@ -4318,16 +4322,29 @@ static void ata_dev_xfermask(struct ata_device *dev)
 	 * drive side as well. Cases where we know a 40wire cable
 	 * is used safely for 80 are not checked here.
 	 */
-	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
-		/* UDMA/44 or higher would be available */
-		if ((ap->cbl == ATA_CBL_PATA40) ||
-		    (ata_is_40wire(dev) &&
-		    (ap->cbl == ATA_CBL_PATA_UNK ||
-		     ap->cbl == ATA_CBL_PATA80))) {
-			ata_dev_printk(dev, KERN_WARNING,
-				 "limited to UDMA/33 due to 40-wire cable\n");
-			xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
+	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA)) {
+                switch (libata_force_cbl) {
+                        case 40:
+				/* limit to UDMA/33 */
+                                ata_dev_printk(dev, KERN_INFO, "forcing 40c\n");
+				xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
+				break;
+                        case 80:
+				/* ignore cable checks */
+                                ata_dev_printk(dev, KERN_INFO, "forcing 80c\n");
+				break;
+			default:
+				/* UDMA/44 or higher would be available */
+				if ((ap->cbl == ATA_CBL_PATA40) ||
+				    (ata_is_40wire(dev) &&
+				    (ap->cbl == ATA_CBL_PATA_UNK ||
+				     ap->cbl == ATA_CBL_PATA80))) {
+					ata_dev_printk(dev, KERN_WARNING,
+						 "limited to UDMA/33 due to 40-wire cable\n");
+					xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
+				}
 		}
+	}
 
 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
 			    &dev->mwdma_mask, &dev->udma_mask);
diff --git a/linux-2.6.24-rc7/drivers/ata/libata-eh.c b/linux-2.6.24-rc7-twam/drivers/ata/libata-eh.c
index f0124a8..7c607e0 100644
--- a/linux-2.6.24-rc7/drivers/ata/libata-eh.c
+++ b/linux-2.6.24-rc7-twam/drivers/ata/libata-eh.c
@@ -2288,9 +2288,27 @@ static int ata_eh_revalidate_and_attach(struct ata_link *link,
 
 	/* PDIAG- should have been released, ask cable type if post-reset */
 	if (ata_is_host_link(link) && ap->ops->cable_detect &&
-	    (ehc->i.flags & ATA_EHI_DID_RESET))
+	    (ehc->i.flags & ATA_EHI_DID_RESET)) {
 		ap->cbl = ap->ops->cable_detect(ap);
 
+		if (!(ap->flags & ATA_FLAG_SATA) && libata_force_cbl) {
+			switch (libata_force_cbl) {
+			case 40:
+				ata_port_printk(ap, KERN_INFO, "forcing 40c\n");
+				ap->cbl = ATA_CBL_PATA40;
+				break;
+			case 80:
+				ata_port_printk(ap, KERN_INFO, "forcing 80c\n");
+				ap->cbl = ATA_CBL_PATA80;
+				break;
+			default:
+				ata_port_printk(ap, KERN_WARNING,
+						"invalid force_cbl value %d\n",
+						libata_force_cbl);
+			}
+		}
+	}
+
 	/* Configure new devices forward such that user doesn't see
 	 * device detection messages backwards.
 	 */
diff --git a/linux-2.6.24-rc7/drivers/ata/libata.h b/linux-2.6.24-rc7-twam/drivers/ata/libata.h
index bbe59c2..b990a8d 100644
--- a/linux-2.6.24-rc7/drivers/ata/libata.h
+++ b/linux-2.6.24-rc7-twam/drivers/ata/libata.h
@@ -60,6 +60,7 @@ extern int atapi_dmadir;
 extern int atapi_passthru16;
 extern int libata_fua;
 extern int libata_noacpi;
+extern int libata_force_cbl;
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 			   u64 block, u32 n_block, unsigned int tf_flags,

[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/x-pkcs7-signature, Size: 3389 bytes --]