* [PATCH v3] arm64: defconfig: increase SERIAL_8250_NR_UARTS
@ 2023-12-01 19:57 ` Francesco Dolcini
0 siblings, 0 replies; 4+ messages in thread
From: Francesco Dolcini @ 2023-12-01 19:57 UTC (permalink / raw
To: linux-arm-kernel, linux-kernel, Arnd Bergmann, Nishanth Menon,
Vignesh Raghavendra
Cc: Francesco Dolcini, Catalin Marinas, Will Deacon, Tero Kristo,
Tony Lindgren
Increase CONFIG_SERIAL_8250_NR_UARTS from 4 to 8, the current legacy value
is not adequate for embedded systems that use SoCs where it's common to
have a large number of serial ports.
No need to change CONFIG_SERIAL_8250_RUNTIME_UARTS, see commit 9d86719f8769
("serial: 8250: Allow using ports higher than SERIAL_8250_RUNTIME_UARTS").
The need to increase this value was noticed while working with Toradex
Verdin AM62, this board has 4 serial UART instances available to the user
plus an internal one that is connected to a Bluetooth module. Without this
change the fifth UART connected to the BT module is not instantiated and BT
is not working.
Instead of increasing the number to the bare minimum (5) that would be
required to solve this specific issue, we increase this to 8 which seems a
more reasonable number to have in the defconfig and should cover more valid
use cases.
With this change the kernel image size increases by ~3.2kB. bloat-o-meter
summary: add/remove: 1/1 grow/shrink: 7/0 up/down: 3220/-8 (3212)
Cc: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Francesco Dolcini <francesco@dolcini.it>
---
v2: added details in the commit message on the verdin am62 uart config and
requirement
v3: added details on the kernel size increase because of this change
---
arch/arm64/configs/defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index b60aa1f89343..ecd365cd1d87 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -448,6 +448,7 @@ CONFIG_SERIO_AMBAKMI=y
CONFIG_LEGACY_PTY_COUNT=16
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_8250_NR_UARTS=8
CONFIG_SERIAL_8250_EXTENDED=y
CONFIG_SERIAL_8250_SHARE_IRQ=y
CONFIG_SERIAL_8250_BCM2835AUX=y
--
2.39.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v3] arm64: defconfig: increase SERIAL_8250_NR_UARTS
@ 2023-12-01 19:57 ` Francesco Dolcini
0 siblings, 0 replies; 4+ messages in thread
From: Francesco Dolcini @ 2023-12-01 19:57 UTC (permalink / raw
To: linux-arm-kernel, linux-kernel, Arnd Bergmann, Nishanth Menon,
Vignesh Raghavendra
Cc: Francesco Dolcini, Catalin Marinas, Will Deacon, Tero Kristo,
Tony Lindgren
Increase CONFIG_SERIAL_8250_NR_UARTS from 4 to 8, the current legacy value
is not adequate for embedded systems that use SoCs where it's common to
have a large number of serial ports.
No need to change CONFIG_SERIAL_8250_RUNTIME_UARTS, see commit 9d86719f8769
("serial: 8250: Allow using ports higher than SERIAL_8250_RUNTIME_UARTS").
The need to increase this value was noticed while working with Toradex
Verdin AM62, this board has 4 serial UART instances available to the user
plus an internal one that is connected to a Bluetooth module. Without this
change the fifth UART connected to the BT module is not instantiated and BT
is not working.
Instead of increasing the number to the bare minimum (5) that would be
required to solve this specific issue, we increase this to 8 which seems a
more reasonable number to have in the defconfig and should cover more valid
use cases.
With this change the kernel image size increases by ~3.2kB. bloat-o-meter
summary: add/remove: 1/1 grow/shrink: 7/0 up/down: 3220/-8 (3212)
Cc: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Francesco Dolcini <francesco@dolcini.it>
---
v2: added details in the commit message on the verdin am62 uart config and
requirement
v3: added details on the kernel size increase because of this change
---
arch/arm64/configs/defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index b60aa1f89343..ecd365cd1d87 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -448,6 +448,7 @@ CONFIG_SERIO_AMBAKMI=y
CONFIG_LEGACY_PTY_COUNT=16
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_8250_NR_UARTS=8
CONFIG_SERIAL_8250_EXTENDED=y
CONFIG_SERIAL_8250_SHARE_IRQ=y
CONFIG_SERIAL_8250_BCM2835AUX=y
--
2.39.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v3] arm64: defconfig: increase SERIAL_8250_NR_UARTS
2023-12-01 19:57 ` Francesco Dolcini
@ 2023-12-04 21:11 ` Nishanth Menon
-1 siblings, 0 replies; 4+ messages in thread
From: Nishanth Menon @ 2023-12-04 21:11 UTC (permalink / raw
To: linux-arm-kernel, linux-kernel, Arnd Bergmann,
Vignesh Raghavendra, Francesco Dolcini
Cc: Nishanth Menon, Catalin Marinas, Will Deacon, Tero Kristo,
Tony Lindgren
Hi Francesco Dolcini,
On Fri, 01 Dec 2023 20:57:32 +0100, Francesco Dolcini wrote:
> Increase CONFIG_SERIAL_8250_NR_UARTS from 4 to 8, the current legacy value
> is not adequate for embedded systems that use SoCs where it's common to
> have a large number of serial ports.
>
> No need to change CONFIG_SERIAL_8250_RUNTIME_UARTS, see commit 9d86719f8769
> ("serial: 8250: Allow using ports higher than SERIAL_8250_RUNTIME_UARTS").
>
> [...]
I have applied the following to branch ti-k3-config-next on [1].
Thank you!
[1/1] arm64: defconfig: increase SERIAL_8250_NR_UARTS
commit: 7bb7d31d9e454fc0b13cb0df44c2b4d953b4a152
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux.git
--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] arm64: defconfig: increase SERIAL_8250_NR_UARTS
@ 2023-12-04 21:11 ` Nishanth Menon
0 siblings, 0 replies; 4+ messages in thread
From: Nishanth Menon @ 2023-12-04 21:11 UTC (permalink / raw
To: linux-arm-kernel, linux-kernel, Arnd Bergmann,
Vignesh Raghavendra, Francesco Dolcini
Cc: Nishanth Menon, Catalin Marinas, Will Deacon, Tero Kristo,
Tony Lindgren
Hi Francesco Dolcini,
On Fri, 01 Dec 2023 20:57:32 +0100, Francesco Dolcini wrote:
> Increase CONFIG_SERIAL_8250_NR_UARTS from 4 to 8, the current legacy value
> is not adequate for embedded systems that use SoCs where it's common to
> have a large number of serial ports.
>
> No need to change CONFIG_SERIAL_8250_RUNTIME_UARTS, see commit 9d86719f8769
> ("serial: 8250: Allow using ports higher than SERIAL_8250_RUNTIME_UARTS").
>
> [...]
I have applied the following to branch ti-k3-config-next on [1].
Thank you!
[1/1] arm64: defconfig: increase SERIAL_8250_NR_UARTS
commit: 7bb7d31d9e454fc0b13cb0df44c2b4d953b4a152
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux.git
--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-12-01 19:57 [PATCH v3] arm64: defconfig: increase SERIAL_8250_NR_UARTS Francesco Dolcini
2023-12-01 19:57 ` Francesco Dolcini
2023-12-04 21:11 ` Nishanth Menon
2023-12-04 21:11 ` Nishanth Menon
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