[U-Boot] [PATCH v2 1/1] core/uclass: iterate over all devices of a uclass

[Andreas Färber]

Am 23.04.2017 um 01:58 schrieb Simon Glass:
> Hi,
> 
> On 19 April 2017 at 15:34, Simon Glass <sjg at chromium.org> wrote:
>> On 19 April 2017 at 15:06, Andreas Färber <afaerber at suse.de> wrote:
>>> Am 19.04.2017 um 13:26 schrieb Heinrich Schuchardt:
>>>> When iterating over the devices of an uclass the iteration stops
>>>> at the first device that cannot be probed.
>>>> When calling booefi this will result in no block device being
>>>
>>> "bootefi"
>>>
>>>> passed to the EFI executable if the first device cannot be probed.
>>>>
>>>> The problem was reported by Andreas Färber in
>>>> https://lists.denx.de/pipermail/u-boot/2017-April/287432.html
>>>>
>>>> For testing I used an odroid-c2 with a dts including
>>>> &sd_emmc_a {
>>>>       status = "okay";
>>>> }
>>>> This device does not exist on the board and cannot be initialized.
>>>>
>>>> With the patch uclass_first_device and uclass_next_device
>>>> iterate internally until they find the first device that can be
>>>> probed or the end of the device list is reached.
>>>>
>>>> Debug output is provided for the two functions.
>>>>
>>>> Reported-by: Andreas Färber <afaerber at suse.de>
>>>> Cc: Simon Glass <sjg at chromium.org>
>>>> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
>>>> ---
>>>> v2:
>>>>   As suggested by Simon Glass correct uclass_first_device() and
>>>>   uclass_next_device() instead of uclass_get_device_tail() to
>>>>   avoid side effects.
>>>> v1:
>>>>   The original patch was posted as
>>>>   core/uclass: uclass_get_device_tail: always set devp
>>>>   https://lists.denx.de/pipermail/u-boot/2017-April/288068.html
>>>> ---
>>>>  drivers/core/uclass.c | 44 +++++++++++++++++++++++++++++++++-----------
>>>>  1 file changed, 33 insertions(+), 11 deletions(-)
>>>
>>> Reviewed-by: Andreas Färber <afaerber at suse.de>
>>> Tested-by: Andreas Färber <afaerber at suse.de>
>>>
>>> Confirming that on my Vega S95 Telos this results in a full GRUB menu,
>>> and GRUB sees two disks.
>>>
>>> Many thanks,
>>>
>>> Andreas
>>
>> Just to be clear, I am NAKing this patch. I do not want to change the
>> existing semantics as it requires existing code to check the function
>> return value. Instead I would like to:
>>
>> - Fix the bug found by Alvaro
>> https://lists.denx.de/pipermail/u-boot/2017-April/288091.html This
>> involves setting *devp to NULL when returning an error.
>> - Add two new functions which return the device whether it probes or
>> not, allowing iteration to continue. Since we have two potential users
>> for these functions, it seems worth it.
>>
>> I'll take a look at this soon unless someone else does :-)
> 
> Here is my attempt:
> 
> http://patchwork.ozlabs.org/patch/752578/
> http://patchwork.ozlabs.org/patch/752576/
> http://patchwork.ozlabs.org/patch/752577/

You have taken my idea with s/available/ok/ and Heinrich's v2 loop
implementation and posted it without Suggested-by or Signed-off-by. :(

Regards,
Andreas

-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)