* disk/ata.c (grub_ata_wait_not_busy): Add debug output of status
register.
(grub_atapi_identify): Add wait after drive select.
(grub_ata_identify): Do more strict status register check before
calling grub_atapi_identify (). Suppress error message if status
register is 0x00 after command failure. Add status register
check after PIO read to avoid bogus identify due to stuck DRQ.
Thanks to Pavel Roskin for testing.
(grub_device_initialize): Remove unsafe status register check.
Thanks to 'phcoder' for problem report and patch.
Prevent sign extension in debug message.