Thread (16 messages) 16 messages, 5 authors, 2024-09-10

Re: [PATCH v4 3/3] tty: serial: samsung: Fix serial rx on Apple A7-A9

From: Kwanghoon Son <hidden>
Date: 2024-09-10 04:15:58
Also in: asahi, linux-arm-kernel, linux-samsung-soc, lkml

On Tue, 2024-09-10 at 10:59 +0800, Nick Chan wrote:
On 10/9/2024 09:59, Kwanghoon Son wrote:
quoted
On Mon, 2024-09-09 at 17:51 +0800, Nick Chan wrote:
quoted
On 9/9/2024 17:43, Kwanghoon Son wrote:
quoted
On Mon, 2024-09-09 at 16:37 +0800, Nick Chan wrote:
quoted
Apple's older A7-A9 SoCs seems to use bit 3 in UTRSTAT as RXTO, which is
enabled by bit 11 in UCON.

Access these bits in addition to the original RXTO and RXTO enable bits,
to allow serial rx to function on A7-A9 SoCs. This change does not
appear to affect the A10 SoC and up.

Signed-off-by: Nick Chan <redacted>
[snip]
quoted
diff --git a/include/linux/serial_s3c.h b/include/linux/serial_s3c.h
index 1e8686695487..964a4fbf2626 100644
--- a/include/linux/serial_s3c.h
+++ b/include/linux/serial_s3c.h
@@ -246,24 +246,28 @@
 				 S5PV210_UFCON_TXTRIG4 |	\
 				 S5PV210_UFCON_RXTRIG4)
 
-#define APPLE_S5L_UCON_RXTO_ENA		9
-#define APPLE_S5L_UCON_RXTHRESH_ENA	12
-#define APPLE_S5L_UCON_TXTHRESH_ENA	13
-#define APPLE_S5L_UCON_RXTO_ENA_MSK	BIT(APPLE_S5L_UCON_RXTO_ENA)
-#define APPLE_S5L_UCON_RXTHRESH_ENA_MSK	BIT(APPLE_S5L_UCON_RXTHRESH_ENA)
-#define APPLE_S5L_UCON_TXTHRESH_ENA_MSK	BIT(APPLE_S5L_UCON_TXTHRESH_ENA)
+#define APPLE_S5L_UCON_RXTO_ENA			9
+#define APPLE_S5L_UCON_RXTO_LEGACY_ENA		11
+#define APPLE_S5L_UCON_RXTHRESH_ENA		12
+#define APPLE_S5L_UCON_TXTHRESH_ENA		13
+#define APPLE_S5L_UCON_RXTO_ENA_MSK		BIT(APPLE_S5L_UCON_RXTO_ENA)
+#define APPLE_S5L_UCON_RXTO_LEGACY_ENA_MSK	BIT(APPLE_S5L_UCON_RXTO_LEGACY_ENA)
+#define APPLE_S5L_UCON_RXTHRESH_ENA_MSK		BIT(APPLE_S5L_UCON_RXTHRESH_ENA)
+#define APPLE_S5L_UCON_TXTHRESH_ENA_MSK		BIT(APPLE_S5L_UCON_TXTHRESH_ENA)
Small thing, but other diff is not needed except
APPLE_S5L_UCON_RXTO_LEGACY_ENA.

Kwang.
The other diffs are there to keep everything aligned, it looks like a
jumbled mess here in the email, but in an editor like nano it is all
aligned, before or after this series.
I know why you did. But still there is way keep aligned and only one
line added. 

you just added one more tab to other lines.
If one tab with APPLE_S5L_UCON_RXTO_LEGACY_ENA, then everything will
fine.

I think less changes better when see git show or blame.
While as you said, APPLE_S5L_UCON_RXTO_LEGACY_ENA would be fine,
APPLE_S5L_UCON_RXTO_LEGACY_ENA_MSK is too long for that to be aligned, see
below without +, - or > distorting everything.

Before:
#define APPLE_S5L_UCON_RXTO_ENA		9
#define APPLE_S5L_UCON_RXTHRESH_ENA	12
#define APPLE_S5L_UCON_TXTHRESH_ENA	13
#define APPLE_S5L_UCON_RXTO_ENA_MSK	(1 << APPLE_S5L_UCON_RXTO_ENA)
#define APPLE_S5L_UCON_RXTHRESH_ENA_MSK	(1 << APPLE_S5L_UCON_RXTHRESH_ENA)
#define APPLE_S5L_UCON_TXTHRESH_ENA_MSK	(1 << APPLE_S5L_UCON_TXTHRESH_ENA)

Patch 1:
#define APPLE_S5L_UCON_RXTO_ENA		9
#define APPLE_S5L_UCON_RXTHRESH_ENA	12
#define APPLE_S5L_UCON_TXTHRESH_ENA	13
#define APPLE_S5L_UCON_RXTO_ENA_MSK	BIT(APPLE_S5L_UCON_RXTO_ENA)
#define APPLE_S5L_UCON_RXTHRESH_ENA_MSK	BIT(APPLE_S5L_UCON_RXTHRESH_ENA)
#define APPLE_S5L_UCON_TXTHRESH_ENA_MSK	BIT(APPLE_S5L_UCON_TXTHRESH_ENA)

After:
#define APPLE_S5L_UCON_RXTO_ENA			9
#define APPLE_S5L_UCON_RXTO_LEGACY_ENA		11
#define APPLE_S5L_UCON_RXTHRESH_ENA		12
#define APPLE_S5L_UCON_TXTHRESH_ENA		13
#define APPLE_S5L_UCON_RXTO_ENA_MSK		BIT(APPLE_S5L_UCON_RXTO_ENA)
#define APPLE_S5L_UCON_RXTO_LEGACY_ENA_MSK
BIT(APPLE_S5L_UCON_RXTO_LEGACY_ENA)
#define APPLE_S5L_UCON_RXTHRESH_ENA_MSK		BIT(APPLE_S5L_UCON_RXTHRESH_ENA)
#define APPLE_S5L_UCON_TXTHRESH_ENA_MSK		BIT(APPLE_S5L_UCON_TXTHRESH_ENA)
Okay I got it.
Thanks for check!

Kwang.
quoted
Best regards,
Kwang.
quoted
quoted
quoted
 
 #define APPLE_S5L_UCON_DEFAULT		(S3C2410_UCON_TXIRQMODE | \
 					 S3C2410_UCON_RXIRQMODE | \
 					 S3C2410_UCON_RXFIFO_TOI)
 #define APPLE_S5L_UCON_MASK		(APPLE_S5L_UCON_RXTO_ENA_MSK | \
+					 APPLE_S5L_UCON_RXTO_LEGACY_ENA_MSK | \
 					 APPLE_S5L_UCON_RXTHRESH_ENA_MSK | \
 					 APPLE_S5L_UCON_TXTHRESH_ENA_MSK)
 
+#define APPLE_S5L_UTRSTAT_RXTO_LEGACY	BIT(3)
 #define APPLE_S5L_UTRSTAT_RXTHRESH	BIT(4)
 #define APPLE_S5L_UTRSTAT_TXTHRESH	BIT(5)
 #define APPLE_S5L_UTRSTAT_RXTO		BIT(9)
-#define APPLE_S5L_UTRSTAT_ALL_FLAGS	(0x3f0)
+#define APPLE_S5L_UTRSTAT_ALL_FLAGS	(0x3f8)
 
 #ifndef __ASSEMBLY__
 
Nick Chan
Nick Chan
  
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