-----Original Message-----
From: Krzysztof Kozlowski <krzk@kernel.org>
Sent: 11 September 2025 20:05

...

Subject: Re: [PATCH 3/3] tty: serial: samsung: Remove unused artpec-8 specific code

On 11/09/2025 16:29, Krzysztof Kozlowski wrote:

quoted

quoted

quoted

--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c

quoted

@@ -2655,8 +2621,6 @@ static const struct of_device_id s3c24xx_uart_dt_match[] = {
                .data = S5L_SERIAL_DRV_DATA },
        { .compatible = "samsung,exynos850-uart",
                .data = EXYNOS850_SERIAL_DRV_DATA },
-       { .compatible = "axis,artpec8-uart",
-               .data = ARTPEC8_SERIAL_DRV_DATA },
        { .compatible = "google,gs101-uart",
                .data = GS101_SERIAL_DRV_DATA },
        { .compatible = "samsung,exynos8895-uart",

@@ -2828,8 +2792,6 @@ OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
                        s5pv210_early_console_setup);
 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
                        s5pv210_early_console_setup);
-OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
-                       s5pv210_early_console_setup);

 static int __init gs101_early_console_setup(struct earlycon_device *device,
                                            const char *opt)

Removing these breaks backwards-compatibility with existing DTBs,
which lack the new "samsung,exynos8895-uart" fallback compatible value.

This was just applied, so ABI break would be fine. It should be however
clearly expressed in the commit msg.

I have a feeling that not much testing was happening in Samsung around
this patchset and only now - after I applied it - some things happen.
But it is damn too late, my tree is already closed which means this is
going to be the ABI.

Ah, no, I mixed up patches with recent DTS for Artpec-8. This serial ABI
was accepted three years ago (!!!), so you are Geert absolutely right -
that's ABI break.

Thank you for your review.

The DTS patches for ARTPEC-8 is added recently (https://lore.kernel.org/linux-samsung-soc/20250901051926.59970-1-ravi.patel@samsung.com/ (local))
Before that, there was no user (in DT) of "axis,artpec8-uart" compatible.
So I am not convinced of ABI break (considering patch #1 and #2 goes first with review comment fixes)

My intension here is to optimize the driver code (by removing kind of duplicated code)
And also preparation of upcoming ARTPEC-9 patch series where ARTPEC-9 uart is
exactly same as ARTPEC-8.

Please let me know if I misunderstood anything here.

Thanks,
Ravi

Folks in Samsung, maybe try to organize some weekly sessions sharing
knowledge after upstreaming reviews/feedbacks? I feel like you are
repeating same mistakes.

Best regards,
Krzysztof