Hi again Wolfgang,
Le 06/09/2010 08:05, Wolfgang Denk a écrit :
Dear Albert ARIBAUD,
In message4C848200.7080401@free.fr you wrote:
First, CONFIG_SYS_IDE_* is for "IDE" (aka "Integrated Drive Electronics"), now usually references as "Parallel ATA", as defined by the underlying AT Attachment (ATA) and AT Attachment Packet Interface (ATAPI) standards. It is my understanding that these standards allow for one or two devices on the bus. So if there was any CONFIG_SYS_IDE_MAXDEVICE_PER_BUS, it would have to be set to 2, which renders it useless.
You're right, and actually this is an overlook on my part, as the current set of port configs has _ATA_ in in addition to _IDE. Would the name CONFIG_SYS_ATA_IDE_MAXDEVICEPERBUS make you be happier?
No. See the AT Attachment (ATA) and AT Attachment Packe Interface (ATAPI) standards.
happens if you want (or need) to setb the limit to 1, and I insert a PCI PATA controller card with 2 devices attached to a bus?
Indeed; and additionally, who says you can only have two IDE busses? I am facing the case right now with the MV88SX6081, which is an 8-ports controller.
But this is NOT an PATA controller, right?
Correct. It is a SATA controller with ATA, not PATA, compatibility.
I have thus started a patch where the CONFIG_SYS_ATA_IDE{0,1}_OFFSET are replaced with a single one, CONFIG_SYS_ATA_IDE_OFFSETS, defined as an open array of values, which allows as many ports as required. For e.g. openrd_base, the config for ATA ports would change from:
We should not use "IDE" code on non-IDE devices. If there are common code parts, these should be split off and generalized as needed (without reference to "ATA" or "IDE").
For IDE as such, I agree. However:
1) Some systems simply do not allow more that one IDE drive for mechanical reasons. I suspect this is the reason behind the CONFIG_SYS_IDE_MAXDEVICE option, which, as such, contradicts IDE since it prevents cmd_ide to handle all 2*MAXBUS devices it could.
2) More generally, the "cmd_ide.c" actually uses ATA to communicate with the devices it manages; thus I feel cmd_ide.c is rightly used when on non-IDE-but-ATA-compatible devices, and that the issue is of naming only.
Besides, since cmd_ide's maximum bus feature is purely a design choice not dictated by standards, I assume your rebuttal addresses maximum devices per bus but not maximum busses, right? Would you agree at least to the minimal idea of having more than two ATA-compatible busses managed by cmd_ide?
/* OpenRD's two kirkwood busses are SATA: 1 device per bux max) */ #define CONFIG_SYS_ATA_IDE_CONFIG { \ { KW_SATA_PORT0_OFFSET, 1}, \ { KW_SATA_PORT1_OFFSET, 1} \
No. It is inherently wrong to use "*IDE*" in combination with a SATA device.
How about this: we could remove "IDE" altogether from config options which are not actually IDE related. This includes CONFIG_SYS_IDE_MAXBUS which is neither IDE- or ATA-related but system-defined
We would then have:
#define CONFIG_SYS_ATA_CONFIG { \
{ KW_SATA_PORT0_OFFSET, 1}, \ { KW_SATA_PORT1_OFFSET, 1} \
We would also remove ATA from non-ATA related symbols used in cmd_ide, but so far the only one I see is CONFIG_SYS_IDE_MAXDEVICE, which is purely a hack to accommodate system limitations; and in my proposal, it would disappear from config files because it equals the sum of the "max device" fields in the struct.
Is this proposal better?
Amicalement,