[PATCH -mm] libata: add human-readable error value decoding v3

[Robert Hancock <hancockr@shaw.ca>]

This adds human-readable decoding of the ATA status and error registers
(similar to what drivers/ide does) as well as the SATA Serror register to
libata error handling output.  This prevents the need to pore through
standards documents to figure out the meaning of the bits in these
registers when looking at error reports.  Some bits that drivers/ide
decoded are not decoded here, since the bits are either command-dependent
or obsolete, and properly parsing them would add too much complexity.

Signed-off-by: Robert Hancock <hancockr@shaw.ca>

---

Rebased to apply to 2.6.23-rc1-mm2.

--- linux-2.6.23-rc1-mm2/include/linux/ata.h	2007-08-02 16:13:24.000000000 -0600
+++ linux-2.6.23-rc1-mm2edit/include/linux/ata.h	2007-08-02 16:37:23.000000000 -0600
@@ -274,6 +274,15 @@ enum {
 	SERR_PROTOCOL		= (1 << 10), /* protocol violation */
 	SERR_INTERNAL		= (1 << 11), /* host internal error */
 	SERR_PHYRDY_CHG		= (1 << 16), /* PHY RDY changed */
+	SERR_PHY_INT_ERR	= (1 << 17), /* PHY internal error */
+	SERR_COMM_WAKE		= (1 << 18), /* Comm wake */
+	SERR_10B_8B_ERR		= (1 << 19), /* 10b to 8b decode error */
+	SERR_DISPARITY		= (1 << 20), /* Disparity */
+	SERR_CRC		= (1 << 21), /* CRC error */
+	SERR_HANDSHAKE		= (1 << 22), /* Handshake error */
+	SERR_LINK_SEQ_ERR	= (1 << 23), /* Link sequence error */
+	SERR_TRANS_ST_ERROR	= (1 << 24), /* Transport state trans. error */
+	SERR_UNRECOG_FIS	= (1 << 25), /* Unrecognized FIS */
 	SERR_DEV_XCHG		= (1 << 26), /* device exchanged */
 
 	/* struct ata_taskfile flags */
--- linux-2.6.23-rc1-mm2/drivers/ata/libata-eh.c	2007-08-02 16:13:11.000000000 -0600
+++ linux-2.6.23-rc1-mm2edit/drivers/ata/libata-eh.c	2007-08-02 16:35:58.000000000 -0600
@@ -1698,6 +1698,27 @@ static void ata_eh_report(struct ata_por
 			ata_port_printk(ap, KERN_ERR, "%s\n", desc);
 	}
 
+	if (ehc->i.serror)
+		ata_port_printk(ap, KERN_ERR,
+		  "SError: {%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s}\n",
+		  ehc->i.serror & SERR_DATA_RECOVERED ? "RecovData " : "",
+		  ehc->i.serror & SERR_COMM_RECOVERED ? "RecovComm " : "",
+		  ehc->i.serror & SERR_DATA ? "UnrecovData " : "",
+		  ehc->i.serror & SERR_PERSISTENT ? "Persist " : "",
+		  ehc->i.serror & SERR_PROTOCOL ? "Proto " : "",
+		  ehc->i.serror & SERR_INTERNAL ? "HostInt " : "",
+		  ehc->i.serror & SERR_PHYRDY_CHG ? "PHYRdyChg " : "",
+		  ehc->i.serror & SERR_PHY_INT_ERR ? "PHYInt " : "",
+		  ehc->i.serror & SERR_COMM_WAKE ? "CommWake " : "",
+		  ehc->i.serror & SERR_10B_8B_ERR ? "10B8B " : "",
+		  ehc->i.serror & SERR_DISPARITY ? "Dispar " : "",
+		  ehc->i.serror & SERR_CRC ? "BadCRC " : "",
+		  ehc->i.serror & SERR_HANDSHAKE ? "Handshk " : "",
+		  ehc->i.serror & SERR_LINK_SEQ_ERR ? "LinkSeq " : "",
+		  ehc->i.serror & SERR_TRANS_ST_ERROR ? "TrStaTrns " : "",
+		  ehc->i.serror & SERR_UNRECOG_FIS ? "UnrecFIS " : "",
+		  ehc->i.serror & SERR_DEV_XCHG ? "DevExch " : "" );
+
 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
 		static const char *dma_str[] = {
 			[DMA_BIDIRECTIONAL]	= "bidi",
@@ -1728,6 +1749,30 @@ static void ata_eh_report(struct ata_por
 			res->hob_lbal, res->hob_lbam, res->hob_lbah,
 			res->device, qc->err_mask, ata_err_string(qc->err_mask),
 			qc->err_mask & AC_ERR_NCQ ? " <F>" : "");
+
+		if (res->command & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ |
+				    ATA_ERR) ) {
+			if (res->command & ATA_BUSY)
+				ata_dev_printk(qc->dev, KERN_ERR,
+				  "status: {Busy}\n" );
+			else
+				ata_dev_printk(qc->dev, KERN_ERR,
+				  "status: {%s%s%s%s}\n",
+				  res->command & ATA_DRDY ? "DRDY " : "",
+				  res->command & ATA_DF ? "DF " : "",
+				  res->command & ATA_DRQ ? "DRQ " : "",
+				  res->command & ATA_ERR ? "ERR " : "" );
+		}
+
+		if (cmd->command != ATA_CMD_PACKET &&
+		    (res->feature & (ATA_ICRC | ATA_UNC | ATA_IDNF |
+				     ATA_ABORTED)))
+			ata_dev_printk(qc->dev, KERN_ERR,
+			  "error: {%s%s%s%s}\n",
+			  res->feature & ATA_ICRC ? "ICRC " : "",
+			  res->feature & ATA_UNC ? "UNC " : "",
+			  res->feature & ATA_IDNF ? "IDNF " : "",
+			  res->feature & ATA_ABORTED ? "ABRT " : "" );
 	}
 }