Hi Wolfgang,
Le 06/09/2010 00:19, Wolfgang Denk a écrit :
Dear Albert ARIBAUD,
In message4C8201CB.9080606@free.fr you wrote:
I think that, rather than modifying IDE_BUS(dev), you should introduce a CONFIG_SYS_IDE_MAXDEVICE_PER_BUS config option that will limit how many devices will be probed for on a given bus. Without this config option, for each bus B there can be up to two devices, numbered (B*2) and (B*2+1); with the config option, there can be only one device numbered (B*2). In all cases, IDE_BUS(dev) can remain defined as (dev>> 1) which will always amount to B.
I'm not happy at all about this.
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?
Second, who says that one setting fits all busses in the system? What 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.
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:
/* ATA bus 0 is Kirkwood port 0 on openrd */ #define CONFIG_SYS_ATA_IDE0_OFFSET KW_SATA_PORT0_OFFSET /* ATA bus 1 is Kirkwood port 1 on openrd */ #define CONFIG_SYS_ATA_IDE1_OFFSET KW_SATA_PORT1_OFFSET
to:
/* OpenRD has two ATA busses, provided by kirkwood */ #define CONFIG_SYS_ATA_IDE_OFFSETS { \ KW_SATA_PORT0_OFFSET, \ KW_SATA_PORT1_OFFSET \ }
I could easily extend my work to account for a maximum number of devices per bus by replacing CONFIG_SYS_ATA_IDE_OFFSETS with a more general CONFIG_SYS_ATA_IDE_CONFIG array of structs which would provide the port offset and maximum devices for each bus:
/* 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} \ }
Sorry, this does not seem to fit IMO.
How about the two suggestions above?
Amicalement,