Hi, We are using MCF5253 procesoor. In this processor we have dedicated ATA DMA controller. Right now we are testing the ATA interface using the PIO and UDMA modes. PIO modes works perfectly. When moving to the UDMA mode, First we configured the ATA DMA controller registers, then we are setting the command in the command register. Before configuring the ATA DMA Misccr Reigster the value of Device status and Alternate status registers is 0x50. After configuring the Misccr Registers the values of status and Alternate status register is 0x0. I don't know why the STATUS register and ALTSTATUS register values are changing when configuring the ATADMA Controller Register. Due to this i am facing HSM violation. Here i have attached the log. scsi0 : pata_fsl ata1: PATA max UDMA/44 cmd 0x800008a0 ctl 0x800008d8 bmdma 0x00000000 irq 147 feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 hob&LBA48: feat 0x0 nsect 0x0, lba 0x0 0x0 0x0 feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 ata1.00: ATA-7: ST380215A, 3.AAD, max UDMA/100 ata1.00: 156301488 sectors, multi 0: LBA48 xfer_mode:c xfer_mode:43 feat 0x3 nsect 0x43 lba 0x0 0x0 0x0 feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 hob&LBA48: feat 0x0 nsect 0x0, lba 0x0 0x0 0x0 feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 ata1.00: configured for UDMA/44 scsi 0:0:0:0: Direct-Access ATA ST380215A 3.AA PQ: 0 ANSI: 5 sd 0:0:0:0: [sda] 156301488 512-byte hardware sectors (80026 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sd 0:0:0:0: [sda] 156301488 512-byte hardware sectors (80026 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sda:feat 0x0 nsect 0x8 lba 0x0 0x0 0x0 sg->address:80020000 Before Setting ATADMA Device Alternate Status Register:50 Source address :18 DMA count register:1000 After setting ATADMA Device Alternate Status Register:50 pata_fsl_bmdma_start starts qc->flags:11 pata_fsl_bmdma_start Read mode Dma Control Register:100 pata_fsl_bmdma_start Read mode Dma Control Register:107 Alternate status Register:0 pata_fsl_bmdma_start ends ata_host_intr: Alternate status register:0 ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 ata1.00: BMDMA stat 0x0 ata1.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 cdb 0x0 data 4096 in res 00/00:00:00:00:00/00:00:00:00:00/00 Emask 0x2 (HSM violation) ata1: soft resetting port feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 ata1.00: revalidation failed (errno=-2) ata1: failed to recover some devices, retrying in 5 secs ata1: soft resetting port feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 ata1.00: revalidation failed (errno=-2) ata1: failed to recover some devices, retrying in 5 secs ata1: soft resetting port feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 ata1.00: revalidation failed (errno=-2) ata1.00: disabled ata1: EH pending after completion, repeating EH (cnt=4) ata1: soft resetting port ata1: EH complete sd 0:0:0:0: [sda] Result: hostbyte=0x04 driverbyte=0x00 end_request: I/O error, dev sda, sector 0 Buffer I/O error on device sda, logical block 0 sd 0:0:0:0: [sda] Result: hostbyte=0x04 driverbyte=0x00 end_request: I/O error, dev sda, sector 0 Buffer I/O error on device sda, logical block 0 unable to read partition table sd 0:0:0:0: [sda] Attached SCSI disk Linux Version : 2.6.23-uc1 Thanks and Regards Sivaji sivaji wrote: > > Hi, > We are using MCF5253 procesoor. In this processor we have dedicated ATA > DMA controller. Right now we are testing the ATA interface using the PIO > and UDMA modes. PIO modes works perfectly. When moving to the UDMA mode, > First we configured the ATA DMA controller registers, then we are setting > the command in the command register. > > Before configuring the ATA DMA Misccr Reigster the value of Device status > and Alternate status registers is 0x50. After configuring the Misccr > Registers the values of status and Alternate status register is 0x0. I > don't know why the STATUS register and ALTSTATUS register values are > changing when configuring the ATADMA Controller Register. Due to this i > am facing HSM violation. Here i have attached the log. Give some idea to > fix this issue. > > Linux Version : 2.6.23-uc1 > > Thanks and Regards > Sivaji > -- View this message in context: http://www.nabble.com/Ultra-DMA-problem-tp18664594p18664647.html Sent from the linux-ide mailing list archive at Nabble.com. -- 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