On Tue, Sep 26, 2023 at 05:52:39PM +0800, yang tylor wrote:

On Tue, Sep 26, 2023 at 5:02 PM Conor Dooley [off-list ref] wrote:

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On Mon, Sep 25, 2023 at 06:16:29PM +0800, yang tylor wrote:

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On Mon, Sep 25, 2023 at 4:41 PM Conor Dooley [off-list ref] wrote:

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On Mon, Sep 25, 2023 at 09:44:21AM +0800, yang tylor wrote:

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On Fri, Sep 22, 2023 at 11:31 PM Conor Dooley [off-list ref] wrote:

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On Fri, Sep 22, 2023 at 05:43:54PM +0800, yang tylor wrote:

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On Fri, Sep 22, 2023 at 5:22 PM Conor Dooley [off-list ref] wrote:

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On Fri, Sep 22, 2023 at 03:56:25PM +0800, yang tylor wrote:

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On Tue, Sep 19, 2023 at 7:09 PM Conor Dooley [off-list ref] wrote:

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On Tue, Sep 19, 2023 at 05:31:29PM +0800, yang tylor wrote:

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The behavior of "himax,boot_time_fw_upgrade" seems not stable and
should be removed. "himax,fw_in_flash", I use the kernel config for
user to select.

That seems like a bad idea, we want to be able to build one kernel that
works for all hardware at the same time.

I see, so I should take that back?
I'll explain more about it.

Are there particular ICs where the firmware would always be in flash and
others where it would never be? Or is this a choice made by the board or
system designer?

Most cases it's about the system designer's decision. But some ICs may be forced
to use flash because of its architecture(multiple IC inside, need to
load firmware to
multiple IC's sram by master IC). But if there is no limitation on
this part, most system
designers will prefer flashless.

Forgive me if I am not understanding correctly, there are some ICs that
will need to load the firmware from flash and there are some where it
will be a decision made by the designer of the board. Is the flash part
of the IC or is it an external flash chip?

Both are possible, it depends on the IC type. For TDDI, the IC is long
and thin, placed on panel PCB, flash will be located at the external
flash chip. For the OLED TP, IC is usually placed at FPC and its flash
is embedded, thus the IC size is large compared to TDDI. But from the
driver's perspective either external flash or embedded flash, the IC
itself will load firmware from flash automatically when reset pin is
released. Only if firmware is loading from the host storage system,
the driver needs to operate the IC in detail.

Since there are ICs that can use the external flash or have it loaded
from the host, it sounds like you do need a property to differentiate
between those cases.

Yep.

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Is it sufficient to just set the firmware-name property for these cases?
If the property exists, then you know you need to load firmware & what
its name is. If it doesn't, then the firmware either isn't needed or
will be automatically loaded from the external flash.

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We have a default prefix firmware name(like himax_xxxx.bin) in the driver code.

How do you intend generating the name of the firmware file? I assume the
same firmware doesn't work on every IC, so you'll need to pick a
different one depending on the compatible?

If considering a firmware library line-up for all the incoming panels
of this driver.
We would use PID as part of the file name. Because all the support panels would
have a unique PID associated. Which will make the firmware name like
himax_xxx_{$PID}.bin. The problem is, we need to know PID before firmware load
at no flash condition. Thus PID information is required in dts when
no-flash-flag
is specified.

Firstly, where does the "xxx" come from?
And you're making it sound more like having firmware-name is suitable
for this use case, given you need to determine the name of the file to
use based on something that is hardware specific but is not
dynamically detectable.

Thanks,
Conor.

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So we'll look for it when no-flash-flag is specified. In our experience,
forcing a prefix firmware name helps the user to aware what firmware
they are dealing with.

If a more simple solution for no-flash condition is needed, as you mentioned,
specifying a firmware name in dts would be the best. Otherwise, a
no-flash-flag and
PID information needs to be added in dts.