mirror_edk2/MdeModulePkg/Bus
Laszlo Ersek dfc229f6a6 MdeModulePkg/.../IdeMode: actualize DRQReady*() comment blocks
The DRQReady() and DRQReady2() functions only differ in that they poll
different status registers for BSY, ERR, and DRQ: the former looks at the
Status Register (clearing interrupt status), while the latter looks at the
Alternate Status Register (not clearing interrupt status).

They both correctly return a unique status code, EFI_NOT_READY, for the

  BSY==0 && ERR==0 && DRQ==0

case; that is, when the device reports "command complete".

However, the functions' leading comments don't explain this case, so it's
easy to miss in callers. Update the comments.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: John Snow <jsnow@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19684 6f19259b-4bc3-4df7-8a09-765794883524
2016-01-19 10:46:34 +00:00
..
Ata MdeModulePkg/.../IdeMode: actualize DRQReady*() comment blocks 2016-01-19 10:46:34 +00:00
I2c/I2cDxe MdeModulePkg: Convert all .uni files to utf-8 2015-12-15 04:56:23 +00:00
Isa/IsaBusDxe MdeModulePkg: Convert all .uni files to utf-8 2015-12-15 04:56:23 +00:00
Pci MdeModulePkg: Add generic PciHostBridgeDxe driver. 2016-01-18 04:50:18 +00:00
Scsi MdeModulePkg/ScsiDisk: Increase the value of SCSI_DISK_TIMEOUT to 30s 2016-01-07 07:03:54 +00:00
Ufs MdeModulePkg/UfsBlockIoPei: Fix MS toolchain /Od 32bit build failure 2016-01-11 02:46:36 +00:00
Usb MdeModulePkg: Convert all .uni files to utf-8 2015-12-15 04:56:23 +00:00