* [PATCH] arm64: dts: qcom: msm8998-mtp: Add alias for blsp1_uart3
@ 2019-11-16 6:44 Bjorn Andersson
2019-11-16 22:24 ` Jeffrey Hugo
0 siblings, 1 reply; 4+ messages in thread
From: Bjorn Andersson @ 2019-11-16 6:44 UTC (permalink / raw)
To: Andy Gross, Bjorn Andersson, Jeffrey Hugo
Cc: linux-arm-msm, devicetree, linux-kernel
The msm_serial driver uses a simple counter to determine which port to
use when no alias is defined, but there's no logic to prevent this from
not colliding with what's defined by the aliases. As a result either
none or all of the active msm_serial instances must be listed as
aliases.
Define blsp1_uart3 as "serial1" to mitigate this problem.
Fixes: 4cffb9f2c700 ("arm64: dts: qcom: msm8998-mtp: Enable bluetooth")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
index 5f101a20a20a..e08fcb426bbf 100644
--- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
@@ -9,6 +9,7 @@
/ {
aliases {
serial0 = &blsp2_uart1;
+ serial1 = &blsp1_uart3;
};
chosen {
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] arm64: dts: qcom: msm8998-mtp: Add alias for blsp1_uart3
2019-11-16 6:44 [PATCH] arm64: dts: qcom: msm8998-mtp: Add alias for blsp1_uart3 Bjorn Andersson
@ 2019-11-16 22:24 ` Jeffrey Hugo
2019-11-18 2:41 ` Bjorn Andersson
0 siblings, 1 reply; 4+ messages in thread
From: Jeffrey Hugo @ 2019-11-16 22:24 UTC (permalink / raw)
To: Bjorn Andersson; +Cc: Andy Gross, MSM, DTML, lkml
On Fri, Nov 15, 2019 at 11:44 PM Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> The msm_serial driver uses a simple counter to determine which port to
> use when no alias is defined, but there's no logic to prevent this from
Which port to use for what, the default console?
> not colliding with what's defined by the aliases. As a result either
> none or all of the active msm_serial instances must be listed as
> aliases.
>
> Define blsp1_uart3 as "serial1" to mitigate this problem.
>
> Fixes: 4cffb9f2c700 ("arm64: dts: qcom: msm8998-mtp: Enable bluetooth")
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
That driver behavior seems like a strange thing to be doing.
If you clarify the question above, -
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
> ---
> arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> index 5f101a20a20a..e08fcb426bbf 100644
> --- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> +++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> @@ -9,6 +9,7 @@
> / {
> aliases {
> serial0 = &blsp2_uart1;
> + serial1 = &blsp1_uart3;
> };
>
> chosen {
> --
> 2.23.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] arm64: dts: qcom: msm8998-mtp: Add alias for blsp1_uart3
2019-11-16 22:24 ` Jeffrey Hugo
@ 2019-11-18 2:41 ` Bjorn Andersson
2019-11-18 15:03 ` Jeffrey Hugo
0 siblings, 1 reply; 4+ messages in thread
From: Bjorn Andersson @ 2019-11-18 2:41 UTC (permalink / raw)
To: Jeffrey Hugo; +Cc: Andy Gross, MSM, DTML, lkml
On Sat 16 Nov 14:24 PST 2019, Jeffrey Hugo wrote:
> On Fri, Nov 15, 2019 at 11:44 PM Bjorn Andersson
> <bjorn.andersson@linaro.org> wrote:
> >
> > The msm_serial driver uses a simple counter to determine which port to
> > use when no alias is defined, but there's no logic to prevent this from
>
> Which port to use for what, the default console?
>
The driver defines three (3) struct uart_ports (wrapped in struct
msm_ports), see msm_uart_port[] around line 1538 in msm_serial.c
This means that you can have a whooping 3 instances of msm_serial in the
system and per the logic found in msm_serial_probe() the allocation
follows the serial%d aliases defined and for entries without an alias a
simple counter, starting at 0 is used.
> > not colliding with what's defined by the aliases. As a result either
> > none or all of the active msm_serial instances must be listed as
> > aliases.
> >
> > Define blsp1_uart3 as "serial1" to mitigate this problem.
> >
> > Fixes: 4cffb9f2c700 ("arm64: dts: qcom: msm8998-mtp: Enable bluetooth")
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>
> That driver behavior seems like a strange thing to be doing.
>
> If you clarify the question above, -
> Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
>
Thanks, I'll respin the message to properly document this behavior.
Regards,
Bjorn
> > ---
> > arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> > index 5f101a20a20a..e08fcb426bbf 100644
> > --- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> > @@ -9,6 +9,7 @@
> > / {
> > aliases {
> > serial0 = &blsp2_uart1;
> > + serial1 = &blsp1_uart3;
> > };
> >
> > chosen {
> > --
> > 2.23.0
> >
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] arm64: dts: qcom: msm8998-mtp: Add alias for blsp1_uart3
2019-11-18 2:41 ` Bjorn Andersson
@ 2019-11-18 15:03 ` Jeffrey Hugo
0 siblings, 0 replies; 4+ messages in thread
From: Jeffrey Hugo @ 2019-11-18 15:03 UTC (permalink / raw)
To: Bjorn Andersson; +Cc: Andy Gross, MSM, DTML, lkml
On Sun, Nov 17, 2019 at 7:41 PM Bjorn Andersson
<bjorn.andersson@linaro.org> wrote:
>
> On Sat 16 Nov 14:24 PST 2019, Jeffrey Hugo wrote:
>
> > On Fri, Nov 15, 2019 at 11:44 PM Bjorn Andersson
> > <bjorn.andersson@linaro.org> wrote:
> > >
> > > The msm_serial driver uses a simple counter to determine which port to
> > > use when no alias is defined, but there's no logic to prevent this from
> >
> > Which port to use for what, the default console?
> >
>
> The driver defines three (3) struct uart_ports (wrapped in struct
> msm_ports), see msm_uart_port[] around line 1538 in msm_serial.c
>
> This means that you can have a whooping 3 instances of msm_serial in the
> system and per the logic found in msm_serial_probe() the allocation
> follows the serial%d aliases defined and for entries without an alias a
> simple counter, starting at 0 is used.
Ah. Clearly no one needs more than 64k of memory, err 3 uart ports :)
>
> > > not colliding with what's defined by the aliases. As a result either
> > > none or all of the active msm_serial instances must be listed as
> > > aliases.
> > >
> > > Define blsp1_uart3 as "serial1" to mitigate this problem.
> > >
> > > Fixes: 4cffb9f2c700 ("arm64: dts: qcom: msm8998-mtp: Enable bluetooth")
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> >
> > That driver behavior seems like a strange thing to be doing.
> >
> > If you clarify the question above, -
> > Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
> >
>
> Thanks, I'll respin the message to properly document this behavior.
Sounds good.
>
> Regards,
> Bjorn
>
> > > ---
> > > arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> > > index 5f101a20a20a..e08fcb426bbf 100644
> > > --- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
> > > @@ -9,6 +9,7 @@
> > > / {
> > > aliases {
> > > serial0 = &blsp2_uart1;
> > > + serial1 = &blsp1_uart3;
> > > };
> > >
> > > chosen {
> > > --
> > > 2.23.0
> > >
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-11-16 6:44 [PATCH] arm64: dts: qcom: msm8998-mtp: Add alias for blsp1_uart3 Bjorn Andersson
2019-11-16 22:24 ` Jeffrey Hugo
2019-11-18 2:41 ` Bjorn Andersson
2019-11-18 15:03 ` Jeffrey Hugo
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