On 10/11/22 16:16, Simon Glass wrote:
Hi Heinrich,
On Tue, 11 Oct 2022 at 04:38, Heinrich Schuchardt
<heinrich.schucha...@canonical.com> wrote:
On 10/11/22 07:46, Heinrich Schuchardt wrote:
On 10/11/22 01:49, Simon Glass wrote:
Hi Heinrich,
On Thu, 6 Oct 2022 at 14:05, Heinrich Schuchardt
<heinrich.schucha...@canonical.com> wrote:
On 10/3/22 18:44, Simon Glass wrote:
Hi Heinrich,
On Mon, 3 Oct 2022 at 10:33, Heinrich Schuchardt
<heinrich.schucha...@canonical.com> wrote:
On 10/3/22 16:57, Simon Glass wrote:
Hi Heinrich,
On Mon, 3 Oct 2022 at 03:36, Heinrich Schuchardt
<heinrich.schucha...@canonical.com> wrote:
On the sandbox I run:
=> setenv efi_selftest block device
=> bootefi selftest
and see the following output:
** Bad device specification host 0 **
Couldn't find partition host 0:0
Cannot read EFI system partition
Running
=> lsblk
yields
Block Driver Devices
-----------------------------
efi_blk : efiloader 0
ide_blk : <none>
mmc_blk : mmc 2, mmc 1, mmc 0
nvme-blk : <none>
sandbox_host_blk : <none>
scsi_blk : <none>
usb_storage_blk : <none>
virtio-blk : <none>
So a efi_blk device was mistaken for a host device.
I continue with
=> host bind 0 ../sandbox.img
=> ls host 0:1
and get the following output:
13 hello.txt
7 u-boot.txt
2 file(s), 0 dir(s)
This is the content of efiblock 0:1 and not of host 0:1 (sic!).
The uclass of the parent device is irrelevant for the
determination of the
uclass of the block device. We must use the uclass stored in the
block
device descriptor.
This issue has been raised repeatedly:
[PATCH 1/1] block: fix blk_get_devnum_by_typename()
https://lore.kernel.org/u-boot/20220802094933.69170-1-heinrich.schucha...@canonical.com/
[PATCH 1/1] blk: simplify blk_get_devnum_by_typename()
https://lore.kernel.org/u-boot/20211023140647.7661-1-heinrich.schucha...@canonical.com/
Yes and you were not able/willing to take on the required work, so
this carried on longer than it should have. I finally did this myself
and it is now in -next.
The refactoring was orthogonal to the problem that I reported and
which
you unfortunately did not consider in the process.
Well it involved using if_type to work around a problem, just making
it harder to get rid of. Overall I am in favour of a faster pace of
migration that we have been following and it would help if people took
on some of this, instead of fixing their little issue.
So we might finally be able to fix this problem properly, since
if_type is mostly just a work-around concept in -next, with just the
fake uclass_id being used at present.
Can you use if_type_to_uclass_id() here, which is the work-around
function for now?
This function does not exist in origin/next. We won't apply this patch
in the 2022-10 cycle.
I think I mean conv_uclass_id() which is the new name.
Let's fix the bug first before thinking about future refactoring.
You may determine the uclass ID for field bdev in struct blk_desc
using
function device_get_uclass_id() when refactoring.
So if you call conv_uclass_id() (without any other refactoring) does
that fix the problem?
Except for UCLASS_USB that function is a NOP. How could it help to
differentiate between devices with the same parent device?
It can't. But the root node should not have UCLASS_BLK children. I
think I mentioned that a few months back?
Would you agree that blk_get_devnum_by_uclass_idname() should not look
at the parent but on the actual device?
No, looking at the parent is exactly what it should do. A block device
is generic, to the extent possible. Its methods are implemented in the
parent uclass and are tightly bound to it. See for example
U_BOOT_DRIVER(mmc_blk) in the MMC uclass.
Let's look at an MMC device
root_driver/soc/mmc@1c0f000/m...@1c0f000.blk is a block device.
What do we need to find out that it can be addressed as mmc 0? The
driver is mmc_blk and its index is 0. We don't need any information
about the parent device at all.
If blk is the MMC block device, the fact that is mmc 0 is determined
by dev_seq(dev_get_parent(blk)). We are not parsing strings to find
that out. It is part of the design.
Unfortunately this confusion is my fault since I used the root device
for the sandbox block devices. That was a convenience and a way to
reduce somewhat the crushing load of driver model migration. But the
time for that convenience is gone and we should create a sandbox host
parent node for the sandbox block devices and tidy up EFI too.
The only confusion is in the current blk_get_devnum_by_uclass_idname()
code looking into the parent device.
The parent device is totally irrelevant here. Stop using it.
See below.
You already noted when writing conv_uclass_id() that using the uclass
name does not work properly to find out the CLI name of a devie.
Can we put the CLI name for device types ("mmc", "scsi" ...) into struct
blk_ops? Then we have a clear separation of the block device from the
parent device.
There really isn't any separation in driver model...the parent device
does determine the type of the block device. It creates the block
device, using its own uclass. See for example mmc-uclass.c in
mmc_bind():
ret = blk_create_devicef(dev, "mmc_blk", "blk", UCLASS_MMC,
dev_seq(dev), 512, 0, &bdev);
The following fields in blk_desc will be dropped at some point:
- uclass_id since it is the same as the parent*
- bdev (point to block device) since we will stop passing around
blk_desc and will use the block device instead
- devnum since it is the save as dev_seq(blk)
* Except for the USB weirdness in conv_uclass_id() which we need to fix
Why do you want this 'separation'? Is this another strange EFI thing
due to it not using driver model properly?
Also you have not yet replied to my point about needing to create a
parent 'media' device for every block device. That is also part of the
design. Have you done that for EFI, or is your reluctance to do that
behind continued discussions and misalignments on UCLASS_BLK ?
If I look at physical devices for MMC I might find:
SoC -> PCI root -> MMC controller -> SD card
What you call MMC parent device is the MMC controller.
This is also what can easily modeled as a device path in EFI.
In the case of an iSCSI drive provided by iPXE U-boot would provide a
network device which currently has a device path VenHW(root)/MAC().
iPXE creates a virtual network card VenHW(root)/MAC()/MAC() consuming
the services of the physical one.
Next it creates a virtual device VenHW(root)/MAC()/MAC()/IPv6() which
exposes the block IO protocol for reading the iSCSI drive.
The parent for the block device in the EFI world is a network interface.
But the block operations are provided by the block IO protocol which is
provided by the virtual device that iPXE has created and not by a
network interface. So the parent is irrelevant here.
Sure you could create a single root2 device as parent for all efi_loader
devices like you have root for the host devices. But such a device would
have no functionality at all except carrying a dummy Uclass to store the
CLI string "efiblk" for all of its children.
Why can't we have the CLI string for the device type in the driver's
struct blk_ops?
Best regards
Heinrich
