tree 9e95f56cc033943f26c21c61377cb7e8ed0d8b4b
parent d10cb35a876c72b4b6711a366e341a1e4d8aa709
author Albert Lee <albertcc@tw.ibm.com> 1132131978 +0800
committer Jeff Garzik <jgarzik@pobox.com> 1132145962 -0500

[PATCH] libata: honor the transfer cycle time speficied by the EIDE device

  The following code segment is not functional because the transfer cycle time speficied by
  the EIDE device is later overwritten by ata_timing_quantize():

	/*
	 * If the drive is an EIDE drive, it can tell us it needs extended
	 * PIO/MW_DMA cycle timing.
	 */
	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
		memset(&p, 0, sizeof(p));
		(snip)
		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
               <== uninitialized "t" is used here
	}

	/*
	 * Convert the timing to bus clock counts.
	 */
	ata_timing_quantize(s, t, T, UT);  <== t is overwritten by quantized s

  The patch has been submitted for ide-timing.h before:
  http://marc.theaimsgroup.com/?l=linux-ide&m=110820013425454&w=2
  Resubmitted for libata.

Changes:
  - Minor fix to honor the following transfer cycle time speficied by the device
    - id[65]: Minimum Multiword DMA transfer cycle time per word
    - id[67]: Minimum PIO transfer cycle time without flow control
    - id[68]: Minimum PIO transfer cycle time with IORDY

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>

=======
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>