RPi: Drain RX queue on setbrg
Subsystems (2)
v2 cover RPi: Drain RX queue on setbrg
We had a few reports coming in from people that had their autoboot chain aborted after pinmuxing support was added for the RPi.
The culprit is easy: The UARTs may have been enabled before, but muxed to an incorrect pin. That pin may have pulled the RX line down which again lead to lots of zero bytes gathered in the RX buffer.
The easy fix for that is to drain the RX queue every time we set the baud rate.
This patch set is the minimally intrusive fix for the RPi. We may want to do that generically for all serial devices later.
v1 -> v2:
- fix pl011 draining
Alexander Graf (2):
serial_bcm283x_mu: Flush RX queue after setting baud rate
bcm283x_pl011: Flush RX queue after setting baud rate
drivers/serial/serial_bcm283x_mu.c | 8 +++++++- drivers/serial/serial_bcm283x_pl011.c | 25 ++++++++++++++++++++++++- drivers/serial/serial_pl01x.c | 10 +++++----- drivers/serial/serial_pl01x_internal.h | 7 ++++++- 4 files changed, 42 insertions(+), 8 deletions(-)
Signature · 1 line
2.12.3
PATCH v2 1/2 serial_bcm283x_mu: Flush RX queue after setting baud rate
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt.
--- drivers/serial/serial_bcm283x_mu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
drivers/serial/serial_bcm283x_mu.c +7 -1
@@ -51,6 +51,8 @@ struct bcm283x_mu_priv {struct bcm283x_mu_regs *regs; }; +static int bcm283x_mu_serial_getc (struct udevice *dev); +static int bcm283x_mu_serial_setbrg (struct udevice *dev,int baudrate) {struct bcm283x_mu_serial_platdata *plat =dev_get_platdata (dev);
@@ -59,13 +61,17 @@ static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate)u32 divider;if (plat->skip_init) -return 0 ; + goto out; divider = plat->clock / (baudrate *8 );writel (BCM283X_MU_LCR_DATA_SIZE_8 , ®s->lcr);writel (divider -1 , ®s->baud); +out: +/* Flush the RX queue - all data in there is bogus */ +while (bcm283x_mu_serial_getc (dev) != -EAGAIN ) ; +return 0 ; }
Signature · 1 line
2.12.3
PATCH v2 1/2 serial_bcm283x_mu: Flush RX queue after setting baud rate
Quoted 5 lines · Alexander Graf
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
Quoted 7 lines
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt.
Fixes caf2233b28 ("bcm283x: Add pinctrl driver")Reported-by Göran Lundberg <[email protected]>Reported-by Peter Robinson <[email protected]>Signed-off-by Alexander Graf <[email protected]>
Quoted 39 lines
--- drivers/serial/serial_bcm283x_mu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)drivers/serial/serial_bcm283x_mu.c +7
-2@@ -51,6 +51,8 @@ struct bcm283x_mu_priv {struct bcm283x_mu_regs *regs; }; +static int bcm283x_mu_serial_getc (struct udevice *dev); +static int bcm283x_mu_serial_setbrg (struct udevice *dev,int baudrate) {struct bcm283x_mu_serial_platdata *plat =dev_get_platdata (dev);@@ -59,13 +61,17 @@ static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate)u32 divider;if (plat->skip_init) -return 0 ; + goto out; divider = plat->clock / (baudrate *8 );writel (BCM283X_MU_LCR_DATA_SIZE_8 , ®s->lcr);writel (divider -1 , ®s->baud); +out: +/* Flush the RX queue - all data in there is bogus */ +while (bcm283x_mu_serial_getc (dev) != -EAGAIN ) ; +return 0 ; } --2.12.3
PATCH v2 1/2 serial_bcm283x_mu: Flush RX queue after setting baud rate
In reply to Alexander GrafQuoted 8 lines · On Wed, 7 Mar 2018 22:08:24 +0100 Alexander Graf <[email protected]> wrote:
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt.
Quoted 8 lines
Fixes caf2233b28 ("bcm283x: Add pinctrl driver")Reported-by Göran Lundberg <[email protected]>Reported-by Peter Robinson <[email protected]>Signed-off-by Alexander Graf <[email protected]>--- drivers/serial/serial_bcm283x_mu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
On a RPi 1, with no enable_uart in config.txt:
PATCH v2 1/2 serial_bcm283x_mu: Flush RX queue after setting baud rate
In reply to Alexander GrafQuoted 8 lines · Alexander Graf
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt.
Quoted 6 lines
Fixes caf2233b28 ("bcm283x: Add pinctrl driver")Reported-by Göran Lundberg <[email protected]>Reported-by Peter Robinson <[email protected]>Signed-off-by Alexander Graf <[email protected]>Tested-by Peter Robinson <[email protected]>Tested-by Tuomas Tynkkynen <[email protected]>
Applied to u-boot/master, thanks!
Signature · 8 lines
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PATCH v2 2/2 bcm283x_pl011: Flush RX queue after setting baud rate
In reply to Alexander GrafAfter the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt on Raspberry Pis that use pl011 for serial.
---
v1 -> v2:
- correctly drain the queue
--- drivers/serial/serial_bcm283x_pl011.c | 25 ++++++++++++++++++++++++- drivers/serial/serial_pl01x.c | 10 +++++----- drivers/serial/serial_pl01x_internal.h | 7 ++++++- 3 files changed, 35 insertions(+), 7 deletions(-)
drivers/serial/serial_bcm283x_pl011.c +24 -1
@@ -9,6 +9,7 @@#include <asm/gpio.h> #include <dm/pinctrl.h> #include <dm/platform_data/serial_pl01x.h> +#include <serial.h> #include "serial_pl01x_internal.h" /*
@@ -55,6 +56,28 @@ static int bcm283x_pl011_serial_ofdata_to_platdata(struct udevice *dev)return 0 ; } +static int bcm283x_pl011_serial_setbrg (struct udevice *dev,int baudrate) +{ +int r; + + r =pl01x_serial_setbrg (dev, baudrate); + +/* +* We may have been muxed to a bogus line before. Drain the RX +* queue so we start at a clean slate. +*/ +while (pl01x_serial_getc (dev) != -EAGAIN ) ; + +return r; +} + +static const struct dm_serial_ops bcm283x_pl011_serial_ops = { + .putc = pl01x_serial_putc, + .pending = pl01x_serial_pending, + .getc = pl01x_serial_getc, + .setbrg = bcm283x_pl011_serial_setbrg, +}; +static const struct udevice_id bcm283x_pl011_serial_id[] = { {.compatible ="brcm,bcm2835-pl011" , .data =TYPE_PL011 }, {}
@@ -67,7 +90,7 @@ U_BOOT_DRIVER(bcm283x_pl011_uart) = { .ofdata_to_platdata = of_match_ptr(bcm283x_pl011_serial_ofdata_to_platdata), .platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata), .probe = pl01x_serial_probe, - .ops = &pl01x_serial_ops, + .ops = &bcm283x_pl011_serial_ops, .flags = DM_FLAG_PRE_RELOC, .priv_auto_alloc_size = sizeof(struct pl01x_priv), };
drivers/serial/serial_pl01x.c +5 -5
@@ -273,7 +273,7 @@ __weak struct serial_device *default_serial_console(void)#ifdef CONFIG_DM_SERIAL -static int pl01x_serial_setbrg (struct udevice *dev,int baudrate) +int pl01x_serial_setbrg (struct udevice *dev,int baudrate) {struct pl01x_serial_platdata *plat =dev_get_platdata (dev);struct pl01x_priv *priv =dev_get_priv (dev);
@@ -299,21 +299,21 @@ int pl01x_serial_probe(struct udevice *dev)return 0 ; } -static int pl01x_serial_getc (struct udevice *dev) +int pl01x_serial_getc (struct udevice *dev) {struct pl01x_priv *priv =dev_get_priv (dev);return pl01x_getc (priv->regs); } -static int pl01x_serial_putc (struct udevice *dev,const char ch) +int pl01x_serial_putc (struct udevice *dev,const char ch) {struct pl01x_priv *priv =dev_get_priv (dev);return pl01x_putc (priv->regs, ch); } -static int pl01x_serial_pending (struct udevice *dev,bool input) +int pl01x_serial_pending (struct udevice *dev,bool input) {struct pl01x_priv *priv =dev_get_priv (dev);unsigned int fr =readl (&priv->regs->fr);
@@ -324,7 +324,7 @@ static int pl01x_serial_pending(struct udevice *dev, bool input)return fr & UART_PL01x_FR_TXFF ?0 :1 ; } -const struct dm_serial_ops pl01x_serial_ops = { +static const struct dm_serial_ops pl01x_serial_ops = { .putc = pl01x_serial_putc, .pending = pl01x_serial_pending, .getc = pl01x_serial_getc,
drivers/serial/serial_pl01x_internal.h +6 -1
@@ -43,7 +43,12 @@ struct pl01x_regs {int pl01x_serial_ofdata_to_platdata (struct udevice *dev);int pl01x_serial_probe (struct udevice *dev); -extern const struct dm_serial_ops pl01x_serial_ops; + +/* Needed for external pl01x_serial_ops drivers */ +int pl01x_serial_putc (struct udevice *dev,const char ch); +int pl01x_serial_pending (struct udevice *dev,bool input); +int pl01x_serial_getc (struct udevice *dev); +int pl01x_serial_setbrg (struct udevice *dev,int baudrate);struct pl01x_priv {struct pl01x_regs *regs;
Signature · 1 line
2.12.3
PATCH v2 2/2 bcm283x_pl011: Flush RX queue after setting baud rate
Quoted 5 lines · Alexander Graf
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
Quoted 7 lines
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt on Raspberry Pis that use pl011 for serial.
Fixes caf2233b28 ("bcm283x: Add pinctrl driver")Reported-by Göran Lundberg <[email protected]>Reported-by Peter Robinson <[email protected]>Signed-off-by Alexander Graf <[email protected]>
Tested on RPi2 and works a lot better, I can boot, interact with the console etc :-)
Quoted 129 lines
---
v1 -> v2:
- correctly drain the queue
--- drivers/serial/serial_bcm283x_pl011.c | 25 ++++++++++++++++++++++++- drivers/serial/serial_pl01x.c | 10 +++++----- drivers/serial/serial_pl01x_internal.h | 7 ++++++- 3 files changed, 35 insertions(+), 7 deletions(-)drivers/serial/serial_bcm283x_pl011.c +24
-1@@ -9,6 +9,7 @@#include <asm/gpio.h> #include <dm/pinctrl.h> #include <dm/platform_data/serial_pl01x.h> +#include <serial.h> #include "serial_pl01x_internal.h" /* @@ -55,6 +56,28 @@ static int bcm283x_pl011_serial_ofdata_to_platdata(struct udevice *dev)return 0 ; } +static int bcm283x_pl011_serial_setbrg (struct udevice *dev,int baudrate) +{ +int r; + + r =pl01x_serial_setbrg (dev, baudrate); + +/* +* We may have been muxed to a bogus line before. Drain the RX +* queue so we start at a clean slate. +*/ +while (pl01x_serial_getc (dev) != -EAGAIN ) ; + +return r; +} + +static const struct dm_serial_ops bcm283x_pl011_serial_ops = { + .putc = pl01x_serial_putc, + .pending = pl01x_serial_pending, + .getc = pl01x_serial_getc, + .setbrg = bcm283x_pl011_serial_setbrg, +}; +static const struct udevice_id bcm283x_pl011_serial_id[] = { {.compatible ="brcm,bcm2835-pl011" , .data =TYPE_PL011 }, {}@@ -67,7 +90,7 @@ U_BOOT_DRIVER(bcm283x_pl011_uart) = { .ofdata_to_platdata = of_match_ptr(bcm283x_pl011_serial_ofdata_to_platdata), .platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata), .probe = pl01x_serial_probe, - .ops = &pl01x_serial_ops, + .ops = &bcm283x_pl011_serial_ops, .flags = DM_FLAG_PRE_RELOC, .priv_auto_alloc_size = sizeof(struct pl01x_priv), };drivers/serial/serial_pl01x.c +5
-5@@ -273,7 +273,7 @@ __weak struct serial_device *default_serial_console(void)#ifdef CONFIG_DM_SERIAL -static int pl01x_serial_setbrg (struct udevice *dev,int baudrate) +int pl01x_serial_setbrg (struct udevice *dev,int baudrate) {struct pl01x_serial_platdata *plat =dev_get_platdata (dev);struct pl01x_priv *priv =dev_get_priv (dev);@@ -299,21 +299,21 @@ int pl01x_serial_probe(struct udevice *dev)return 0 ; } -static int pl01x_serial_getc (struct udevice *dev) +int pl01x_serial_getc (struct udevice *dev) {struct pl01x_priv *priv =dev_get_priv (dev);return pl01x_getc (priv->regs); } -static int pl01x_serial_putc (struct udevice *dev,const char ch) +int pl01x_serial_putc (struct udevice *dev,const char ch) {struct pl01x_priv *priv =dev_get_priv (dev);return pl01x_putc (priv->regs, ch); } -static int pl01x_serial_pending (struct udevice *dev,bool input) +int pl01x_serial_pending (struct udevice *dev,bool input) {struct pl01x_priv *priv =dev_get_priv (dev);unsigned int fr =readl (&priv->regs->fr);@@ -324,7 +324,7 @@ static int pl01x_serial_pending(struct udevice *dev, bool input)return fr & UART_PL01x_FR_TXFF ?0 :1 ; } -const struct dm_serial_ops pl01x_serial_ops = { +static const struct dm_serial_ops pl01x_serial_ops = { .putc = pl01x_serial_putc, .pending = pl01x_serial_pending, .getc = pl01x_serial_getc,drivers/serial/serial_pl01x_internal.h +6
-2@@ -43,7 +43,12 @@ struct pl01x_regs {int pl01x_serial_ofdata_to_platdata (struct udevice *dev);int pl01x_serial_probe (struct udevice *dev); -extern const struct dm_serial_ops pl01x_serial_ops; + +/* Needed for external pl01x_serial_ops drivers */ +int pl01x_serial_putc (struct udevice *dev,const char ch); +int pl01x_serial_pending (struct udevice *dev,bool input); +int pl01x_serial_getc (struct udevice *dev); +int pl01x_serial_setbrg (struct udevice *dev,int baudrate);struct pl01x_priv {struct pl01x_regs *regs; --2.12.3
PATCH v2 2/2 bcm283x_pl011: Flush RX queue after setting baud rate
In reply to Alexander GrafQuoted 15 lines · On Wed, 7 Mar 2018 22:08:25 +0100 Alexander Graf <[email protected]> wrote:
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt on Raspberry Pis that use pl011 for serial.
Fixes caf2233b28 ("bcm283x: Add pinctrl driver")Reported-by Göran Lundberg <[email protected]>Reported-by Peter Robinson <[email protected]>Signed-off-by Alexander Graf <[email protected]>---
Quoted 9 lines
v1 -> v2:
- correctly drain the queue
--- drivers/serial/serial_bcm283x_pl011.c | 25 ++++++++++++++++++++++++- drivers/serial/serial_pl01x.c | 10 +++++----- drivers/serial/serial_pl01x_internal.h | 7 ++++++- 3 files changed, 35 insertions(+), 7 deletions(-)
On a RPi 1, with no enable_uart in config.txt:
PATCH v2 2/2 bcm283x_pl011: Flush RX queue after setting baud rate
In reply to Alexander GrafQuoted 8 lines · Alexander Graf
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before.
So let's flush the RX queue whenever we initialize baud rates.
This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt on Raspberry Pis that use pl011 for serial.
Quoted 6 lines
Fixes caf2233b28 ("bcm283x: Add pinctrl driver")Reported-by Göran Lundberg <[email protected]>Reported-by Peter Robinson <[email protected]>Signed-off-by Alexander Graf <[email protected]>Tested-by Peter Robinson <[email protected]>Tested-by Tuomas Tynkkynen <[email protected]>
Applied to u-boot/master, thanks!
Signature · 8 lines
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