The attached patch should fix this. It should also prevents misleading
error messages if a device does not exist.
2009-05-20 Christian Franke <fra...@computer.org>
* disk/ata.c: (grub_ata_wait_not_busy): Add debug output of status
register.
(grub_ata_identify): Suppress error message if status register
is 0x00 after command failure.
(grub_device_initialize): Remove unsafe status register check.
Thanks to 'phcoder' for problem report and patch.
Prevent sign extension in debug message.
--
Regards,
Christian Franke
diff --git a/disk/ata.c b/disk/ata.c
index ea42d59..651937d 100644
--- a/disk/ata.c
+++ b/disk/ata.c
@@ -41,11 +41,14 @@ grub_ata_wait_not_busy (struct grub_ata_device *dev, int milliseconds)
grub_millisleep (1);
int i = 1;
- while (grub_ata_regget (dev, GRUB_ATA_REG_STATUS) & GRUB_ATA_STATUS_BUSY)
+ grub_uint8_t sts;
+ while ((sts = grub_ata_regget (dev, GRUB_ATA_REG_STATUS))
+ & GRUB_ATA_STATUS_BUSY)
{
if (i >= milliseconds)
{
- grub_dprintf ("ata", "timeout: %dms\n", milliseconds);
+ grub_dprintf ("ata", "timeout: %dms, status=0x%x\n",
+ milliseconds, sts);
return grub_error (GRUB_ERR_TIMEOUT, "ATA timeout");
}
@@ -259,20 +262,21 @@ grub_ata_identify (struct grub_ata_device *dev)
if (grub_ata_wait_drq (dev, 0, GRUB_ATA_TOUT_STD))
{
+ grub_free(info);
+ grub_errno = GRUB_ERR_NONE;
+
if (grub_ata_regget (dev, GRUB_ATA_REG_ERROR) & 0x04) /* ABRT */
- {
- /* Device without ATA IDENTIFY, try ATAPI. */
- grub_free(info);
- grub_errno = GRUB_ERR_NONE;
- return grub_atapi_identify (dev);
- }
+ /* Device without ATA IDENTIFY, try ATAPI. */
+ return grub_atapi_identify (dev);
+
+ else if (grub_ata_regget (dev, GRUB_ATA_REG_STATUS) == 0x00)
+ /* No device, return error but don't print message. */
+ return GRUB_ERR_UNKNOWN_DEVICE;
+
else
- {
- /* Error. */
- grub_free(info);
- return grub_error (GRUB_ERR_UNKNOWN_DEVICE,
- "device can not be identified");
- }
+ /* Other Error. */
+ return grub_error (GRUB_ERR_UNKNOWN_DEVICE,
+ "device can not be identified");
}
grub_ata_pio_read (dev, info, GRUB_DISK_SECTOR_SIZE);
@@ -334,26 +338,12 @@ grub_ata_device_initialize (int port, int device, int addr, int addr2)
grub_ata_regset (dev, GRUB_ATA_REG_DISK, dev->device << 4);
grub_ata_wait ();
- /* If status is 0x00, it is safe to assume that there
- is no device (or only a !READY) device connected. */
- grub_int8_t sts = grub_ata_regget (dev, GRUB_ATA_REG_STATUS);
- grub_dprintf ("ata", "status=0x%x\n", sts);
- if (sts == 0x00)
- {
- grub_free(dev);
- return 0;
- }
-
/* Try to detect if the port is in use by writing to it,
waiting for a while and reading it again. If the value
- was preserved, there is a device connected.
- But this tests often detects a second (slave) device
- connected to a SATA controller which supports only one
- (master) device. In this case, the status register
- check above usually works. */
+ was preserved, there is a device connected. */
grub_ata_regset (dev, GRUB_ATA_REG_SECTORS, 0x5A);
grub_ata_wait ();
- grub_int8_t sec = grub_ata_regget (dev, GRUB_ATA_REG_SECTORS);
+ grub_uint8_t sec = grub_ata_regget (dev, GRUB_ATA_REG_SECTORS);
grub_dprintf ("ata", "sectors=0x%x\n", sec);
if (sec != 0x5A)
{
@@ -361,6 +351,12 @@ grub_ata_device_initialize (int port, int device, int addr, int addr2)
return 0;
}
+ /* The above test may detect a second (slave) device
+ connected to a SATA controller which supports only one
+ (master) device. It is not safe to use the status register
+ READY bit to check for controller channel existence. Some
+ ATAPI commands (RESET, DIAGNOSTIC) may clear this bit. */
+
/* Use the IDENTIFY DEVICE command to query the device. */
if (grub_ata_identify (dev))
{
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