On Fri, Apr 9, 2010 at 11:54 AM, Onkar Mahajan <kern.devel@xxxxxxxxx> wrote: > Thank you very much sir. That was a good advise. > I will try to do that. But , If I face difficulties is there > any mailing list wherein I can post SATA related questions. I found one link for WD: http://ssdportal.wdc.com/documents/datasheets/5000FS.pdf somewhere in page 17 are the ATA commands for examples.... SATA mailing list may be your alternatives? (search for "linux-ide" at http://vger.kernel.org/vger-lists.html, or perhaps many others?) > > Thanks & regards, > Onkar > > On Fri, Apr 9, 2010 at 8:59 AM, Peter Teoh <htmldeveloper@xxxxxxxxx> wrote: >> >> On Wed, Apr 7, 2010 at 1:49 PM, Onkar Mahajan <kern.devel@xxxxxxxxx> >> wrote: >> > Greg, >> > My intention is to learn to write a SATA driver with the hardware >> > that I have. I have a SATA hard drive from Western Digital (MDL : >> > WD800JD-75MSAS) >> > and SATA controller (Intel 82801 GB/GR/GH ( ICH7 family ) for which the >> > drivers are already >> > present. I want to unload the drivers and reverse engineer them and make >> > them working. >> > Is it a good way to learn SATA/SCSI drivers ?? Please guide me with your >> > invaluable experience. >> > >> >> Not sure if it is useful to you or not, but the following are >> extracted from my emails to my students working on the SATA drivers >> right now :-) (sorry I did not have time to edit it...but if u >> learning....just absorbed everything :-), and if u have time, find the >> differences between the current drivers and those of the datasheet, so >> as to add in new functionalities to the drivers. >> but....but...but.....this is easier said than done....even for >> me!!!!). >> >> Looking up the datasheet (WD u must find for yourself): >> >> http://www.seagate.com/support/disc/manuals/sata/100402371a.pdf >> >> Looking further into page 47: >> >> Supported ATA commands >> >> The following table lists Serial ATA standard commands that the drive >> supports. For a detailed description of the ATA commands, refer to the >> Serial ATA: High Speed Serialized AT Attachment specification. See >> “S.M.A.R.T. commands” on page 44.for details and subcommands used in >> the S.M.A.R.T. implementation. >> >> A list of all the command supported is listed: >> >> Identify Device >> ECH >> Idle >> 97H or E3H >> >> which is inside drivers/ata/libata-eh.c: >> >> 2135 const char *ata_get_cmd_descript(u8 command) >> 2136 { >> 2137 #ifdef CONFIG_ATA_VERBOSE_ERROR >> 2138 static const struct >> 2139 { >> 2140 u8 command; >> 2141 const char *text; >> 2142 } cmd_descr[] = { >> 2143 { ATA_CMD_DEV_RESET, "DEVICE RESET" }, >> 2144 { ATA_CMD_CHK_POWER, "CHECK POWER MODE" }, >> 2145 { ATA_CMD_STANDBY, "STANDBY" }, >> 2146 { ATA_CMD_IDLE, "IDLE" }, >> 2147 { ATA_CMD_EDD, "EXECUTE DEVICE >> DIAGNOSTIC" }, >> 2148 { ATA_CMD_DOWNLOAD_MICRO, "DOWNLOAD MICROCODE" >> }, >> 2149 { ATA_CMD_NOP, "NOP" }, >> 2150 { ATA_CMD_FLUSH, "FLUSH CACHE" }, >> 2151 { ATA_CMD_FLUSH_EXT, "FLUSH CACHE EXT" }, >> 2152 { ATA_CMD_ID_ATA, "IDENTIFY DEVICE" >> },========================> >> 2153 { ATA_CMD_ID_ATAPI, "IDENTIFY PACKET >> DEVICE" }, >> >> and this is called inside libata-acpi.c: >> >> 663 /** >> 664 * ata_acpi_run_tf - send taskfile registers to host controller >> 665 * @dev: target ATA device >> 666 * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7) >> 667 * >> 668 * Outputs ATA taskfile to standard ATA host controller using MMIO >> 669 * or PIO as indicated by the ATA_FLAG_MMIO flag. >> 670 * Writes the control, feature, nsect, lbal, lbam, and lbah >> registers. >> 671 * Optionally (ATA_TFLAG_LBA48) writes hob_feature, hob_nsect, >> 672 * hob_lbal, hob_lbam, and hob_lbah. >> 673 * >> 674 * This function waits for idle (!BUSY and !DRQ) after writing >> 675 * registers. If the control register has a new value, this >> 676 * function also waits for idle after writing control and before >> 677 * writing the remaining registers. >> 678 * >> 679 * LOCKING: >> 680 * EH context. >> 681 * >> 682 * RETURNS: >> 683 * 1 if command is executed successfully. 0 if ignored, rejected or >> 684 * filtered out, -errno on other errors. >> 685 */ >> 686 static int ata_acpi_run_tf(struct ata_device *dev, >> 687 const struct ata_acpi_gtf *gtf, >> 688 const struct ata_acpi_gtf *prev_gtf) >> 689 { >> 690 struct ata_taskfile *pptf = NULL; >> 691 struct ata_taskfile tf, ptf, rtf; >> 692 unsigned int err_mask; >> 693 const char *level; >> 694 const char *descr; >> 695 char msg[60]; >> 696 int rc; >> 697 >> 698 if ((gtf->tf[0] == 0) && (gtf->tf[1] == 0) && (gtf->tf[2] == >> 0) >> 699 && (gtf->tf[3] == 0) && (gtf->tf[4] == 0) && (gtf->tf[5] >> == 0) >> 700 && (gtf->tf[6] == 0)) >> 701 return 0; >> 702 >> 703 ata_acpi_gtf_to_tf(dev, gtf, &tf); >> 704 if (prev_gtf) { >> 705 ata_acpi_gtf_to_tf(dev, prev_gtf, &ptf); >> 706 pptf = &ptf; >> 707 } >> 708 >> 709 if (!ata_acpi_filter_tf(dev, &tf, pptf)) { >> 710 rtf = tf; >> 711 err_mask = ata_exec_internal(dev, &rtf, NULL, >> 712 DMA_NONE, NULL, 0, 0); >> 713 >> 714 switch (err_mask) { >> 715 case 0: >> 716 level = KERN_DEBUG; >> 717 snprintf(msg, sizeof(msg), "succeeded"); >> 718 rc = 1; >> 719 break; >> 720 >> 721 case AC_ERR_DEV: >> 722 level = KERN_INFO; >> 723 snprintf(msg, sizeof(msg), >> 724 "rejected by device (Stat=0x%02x >> Err=0x%02x)", >> 725 rtf.command, rtf.feature); >> 726 rc = 0; >> 727 break; >> 728 >> 729 default: >> 730 level = KERN_ERR; >> 731 snprintf(msg, sizeof(msg), >> 732 "failed (Emask=0x%x Stat=0x%02x >> Err=0x%02x)", >> 733 err_mask, rtf.command, rtf.feature); >> 734 rc = -EIO; >> 735 break; >> 736 } >> 737 } else { >> 738 level = KERN_INFO; >> 739 snprintf(msg, sizeof(msg), "filtered out"); >> 740 rc = 0; >> 741 } >> 742 descr = ata_get_cmd_descript(tf.command); >> 743 >> >> >> And the systemtap tracing: >> >> ata_scsi_queuecmd >> 0xffffffff8162c26d : ata_scsi_queuecmd+0x0/0x98 [kernel] >> 0xffffffff81515625 : scsi_dispatch_cmd+0x1e1/0x25f [kernel] >> 0xffffffff8151b43b : scsi_request_fn+0x3f2/0x53b [kernel] >> 0xffffffff813bb641 : __generic_unplug_device+0x35/0x39 [kernel] >> 0xffffffff813bb673 : generic_unplug_device+0x2e/0x3e [kernel] >> 0xffffffff813b63a6 : blk_unplug+0x48/0x4d [kernel] >> 0xffffffff813b63bd : blk_backing_dev_unplug+0x12/0x14 [kernel] >> 0xffffffff8114084f : sync_buffer+0x3e/0x47 [kernel] >> 0xffffffff81d9b33c : __wait_on_bit+0x4c/0x7e [kernel] >> 0xffffffff81d9b3dd : out_of_line_wait_on_bit+0x6f/0x7c [kernel] >> 0xffffffff81140774 : __wait_on_buffer+0x24/0x26 [kernel] >> 0xffffffff81205523 : wait_on_buffer+0x3d/0x41 [kernel] >> 0xffffffff81206138 : journal_commit_transaction+0xb42/0x117a [kernel] >> 0xffffffff8120961a : kjournald+0x102/0x25f [kernel] >> 0xffffffff81083c43 : kthread+0x9d/0xa5 [kernel] >> 0xffffffff81030634 : kernel_thread_helper+0x4/0x10 [kernel] >> 0xffffffff81d9d53c : restore_args+0x0/0x30 [kernel] (inexact) >> 0xffffffff81083ba6 : kthread+0x0/0xa5 [kernel] (inexact) >> 0xffffffff81030630 : kernel_thread_helper+0x0/0x10 [kernel] (inexact) >> >> ata_scsi_find_dev >> 0xffffffff816292b1 : ata_scsi_find_dev+0x0/0x39 [kernel] >> 0xffffffff8162c2b6 : ata_scsi_queuecmd+0x49/0x98 [kernel] >> 0xffffffff81515625 : scsi_dispatch_cmd+0x1e1/0x25f [kernel] >> 0xffffffff8151b43b : scsi_request_fn+0x3f2/0x53b [kernel] >> 0xffffffff813bb641 : __generic_unplug_device+0x35/0x39 [kernel] >> 0xffffffff813bb673 : generic_unplug_device+0x2e/0x3e [kernel] >> 0xffffffff813b63a6 : blk_unplug+0x48/0x4d [kernel] >> 0xffffffff813b63bd : blk_backing_dev_unplug+0x12/0x14 [kernel] >> 0xffffffff8114084f : sync_buffer+0x3e/0x47 [kernel] >> 0xffffffff81d9b33c : __wait_on_bit+0x4c/0x7e [kernel] >> 0xffffffff81d9b3dd : out_of_line_wait_on_bit+0x6f/0x7c [kernel] >> 0xffffffff81140774 : __wait_on_buffer+0x24/0x26 [kernel] >> 0xffffffff81205523 : wait_on_buffer+0x3d/0x41 [kernel] >> 0xffffffff81206138 : journal_commit_transaction+0xb42/0x117a [kernel] >> 0xffffffff8120961a : kjournald+0x102/0x25f [kernel] >> 0xffffffff81083c43 : kthread+0x9d/0xa5 [kernel] >> 0xffffffff81030634 : kernel_thread_helper+0x4/0x10 [kernel] >> 0xffffffff81d9d53c : restore_args+0x0/0x30 [kernel] (inexact) >> 0xffffffff81083ba6 : kthread+0x0/0xa5 [kernel] (inexact) >> 0xffffffff81030630 : kernel_thread_helper+0x0/0x10 [kernel] (inexact) >> >> __ata_scsi_find_dev >> 0xffffffff816291ff : __ata_scsi_find_dev+0x0/0xb2 [kernel] >> 0xffffffff816292bf : ata_scsi_find_dev+0xe/0x39 [kernel] >> 0xffffffff8162c2b6 : ata_scsi_queuecmd+0x49/0x98 [kernel] >> 0xffffffff81515625 : scsi_dispatch_cmd+0x1e1/0x25f [kernel] >> 0xffffffff8151b43b : scsi_request_fn+0x3f2/0x53b [kernel] >> 0xffffffff813bb641 : __generic_unplug_device+0x35/0x39 [kernel] >> >> which is output by: >> >> probe kernel.function("*@drivers/ata/libata*.c") { >> printf("%s\n", probefunc()); >> print_backtrace(); >> printf("\n"); >> } >> >> -- >> Regards, >> Peter Teoh > > -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
