* [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
@ 2015-08-20 15:52 ` Guenter Roeck
0 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2015-08-20 15:52 UTC (permalink / raw)
To: Peter Chubb; +Cc: qemu-trivial, qemu-devel, Guenter Roeck
Generate an interrupt if the tx buffer is empty and the tx empty interrupt
is enabled. This fixes a problem seen when running a Linux image since
Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
from imx_start_tx()"). Linux now waits for the tx empty interrupt before
starting to send data, causing transmit stalls until there is an interrupt
for another reason.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
hw/char/imx_serial.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
index f3fbc77..8dc791d 100644
--- a/hw/char/imx_serial.c
+++ b/hw/char/imx_serial.c
@@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
uint32_t flags;
flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
- if (!(s->ucr1 & UCR1_TXMPTYEN)) {
+ if (s->ucr1 & UCR1_TXMPTYEN) {
+ flags |= (s->uts1 & UTS1_TXEMPTY);
+ } else {
flags &= ~USR1_TRDY;
}
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [Qemu-devel] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
@ 2015-08-20 15:52 ` Guenter Roeck
0 siblings, 0 replies; 8+ messages in thread
From: Guenter Roeck @ 2015-08-20 15:52 UTC (permalink / raw)
To: Peter Chubb; +Cc: qemu-trivial, qemu-devel, Guenter Roeck
Generate an interrupt if the tx buffer is empty and the tx empty interrupt
is enabled. This fixes a problem seen when running a Linux image since
Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
from imx_start_tx()"). Linux now waits for the tx empty interrupt before
starting to send data, causing transmit stalls until there is an interrupt
for another reason.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
hw/char/imx_serial.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
index f3fbc77..8dc791d 100644
--- a/hw/char/imx_serial.c
+++ b/hw/char/imx_serial.c
@@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
uint32_t flags;
flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
- if (!(s->ucr1 & UCR1_TXMPTYEN)) {
+ if (s->ucr1 & UCR1_TXMPTYEN) {
+ flags |= (s->uts1 & UTS1_TXEMPTY);
+ } else {
flags &= ~USR1_TRDY;
}
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
2015-08-20 15:52 ` [Qemu-devel] " Guenter Roeck
@ 2015-09-11 7:37 ` Michael Tokarev
-1 siblings, 0 replies; 8+ messages in thread
From: Michael Tokarev @ 2015-09-11 7:37 UTC (permalink / raw)
To: Guenter Roeck, Peter Chubb; +Cc: qemu-trivial, qemu-devel
Can we please have some r-b or ACK for this? :)
20.08.2015 18:52, Guenter Roeck wrote:
> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
> is enabled. This fixes a problem seen when running a Linux image since
> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
> starting to send data, causing transmit stalls until there is an interrupt
> for another reason.
>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> hw/char/imx_serial.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
> index f3fbc77..8dc791d 100644
> --- a/hw/char/imx_serial.c
> +++ b/hw/char/imx_serial.c
> @@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
> uint32_t flags;
>
> flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
> - if (!(s->ucr1 & UCR1_TXMPTYEN)) {
> + if (s->ucr1 & UCR1_TXMPTYEN) {
> + flags |= (s->uts1 & UTS1_TXEMPTY);
> + } else {
> flags &= ~USR1_TRDY;
> }
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Qemu-devel] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
@ 2015-09-11 7:37 ` Michael Tokarev
0 siblings, 0 replies; 8+ messages in thread
From: Michael Tokarev @ 2015-09-11 7:37 UTC (permalink / raw)
To: Guenter Roeck, Peter Chubb; +Cc: qemu-trivial, qemu-devel
Can we please have some r-b or ACK for this? :)
20.08.2015 18:52, Guenter Roeck wrote:
> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
> is enabled. This fixes a problem seen when running a Linux image since
> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
> starting to send data, causing transmit stalls until there is an interrupt
> for another reason.
>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> hw/char/imx_serial.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
> index f3fbc77..8dc791d 100644
> --- a/hw/char/imx_serial.c
> +++ b/hw/char/imx_serial.c
> @@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
> uint32_t flags;
>
> flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
> - if (!(s->ucr1 & UCR1_TXMPTYEN)) {
> + if (s->ucr1 & UCR1_TXMPTYEN) {
> + flags |= (s->uts1 & UTS1_TXEMPTY);
> + } else {
> flags &= ~USR1_TRDY;
> }
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Qemu-trivial] [Qemu-devel] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
2015-09-11 7:37 ` [Qemu-devel] " Michael Tokarev
@ 2015-09-13 20:17 ` Peter Crosthwaite
-1 siblings, 0 replies; 8+ messages in thread
From: Peter Crosthwaite @ 2015-09-13 20:17 UTC (permalink / raw)
To: Michael Tokarev, Jean-Christophe Dubois
Cc: qemu-trivial, Peter Chubb, qemu-devel@nongnu.org Developers,
Guenter Roeck
On Fri, Sep 11, 2015 at 12:37 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>
> Can we please have some r-b or ACK for this? :)
>
> 20.08.2015 18:52, Guenter Roeck wrote:
>> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
>> is enabled. This fixes a problem seen when running a Linux image since
>> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
>> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
>> starting to send data, causing transmit stalls until there is an interrupt
>> for another reason.
>>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Looks right, Jean-Christophe may know more though.
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
>> ---
>> hw/char/imx_serial.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
>> index f3fbc77..8dc791d 100644
>> --- a/hw/char/imx_serial.c
>> +++ b/hw/char/imx_serial.c
>> @@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
>> uint32_t flags;
>>
>> flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
>> - if (!(s->ucr1 & UCR1_TXMPTYEN)) {
>> + if (s->ucr1 & UCR1_TXMPTYEN) {
>> + flags |= (s->uts1 & UTS1_TXEMPTY);
>> + } else {
>> flags &= ~USR1_TRDY;
Out of scope, but this conditional looks wrong (in original code too).
Why does TXMPTYEN gate TRDY?
Regards,
Peter
>> }
>>
>>
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Qemu-devel] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
@ 2015-09-13 20:17 ` Peter Crosthwaite
0 siblings, 0 replies; 8+ messages in thread
From: Peter Crosthwaite @ 2015-09-13 20:17 UTC (permalink / raw)
To: Michael Tokarev, Jean-Christophe Dubois
Cc: qemu-trivial, Peter Chubb, qemu-devel@nongnu.org Developers,
Guenter Roeck
On Fri, Sep 11, 2015 at 12:37 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>
> Can we please have some r-b or ACK for this? :)
>
> 20.08.2015 18:52, Guenter Roeck wrote:
>> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
>> is enabled. This fixes a problem seen when running a Linux image since
>> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
>> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
>> starting to send data, causing transmit stalls until there is an interrupt
>> for another reason.
>>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Looks right, Jean-Christophe may know more though.
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
>> ---
>> hw/char/imx_serial.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
>> index f3fbc77..8dc791d 100644
>> --- a/hw/char/imx_serial.c
>> +++ b/hw/char/imx_serial.c
>> @@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
>> uint32_t flags;
>>
>> flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
>> - if (!(s->ucr1 & UCR1_TXMPTYEN)) {
>> + if (s->ucr1 & UCR1_TXMPTYEN) {
>> + flags |= (s->uts1 & UTS1_TXEMPTY);
>> + } else {
>> flags &= ~USR1_TRDY;
Out of scope, but this conditional looks wrong (in original code too).
Why does TXMPTYEN gate TRDY?
Regards,
Peter
>> }
>>
>>
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
2015-09-13 20:17 ` Peter Crosthwaite
@ 2015-09-16 10:28 ` Michael Tokarev
-1 siblings, 0 replies; 8+ messages in thread
From: Michael Tokarev @ 2015-09-16 10:28 UTC (permalink / raw)
To: Peter Crosthwaite, Jean-Christophe Dubois
Cc: qemu-trivial, Peter Chubb, qemu-devel@nongnu.org Developers,
Guenter Roeck
13.09.2015 23:17, Peter Crosthwaite wrote:
> On Fri, Sep 11, 2015 at 12:37 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>>
>> Can we please have some r-b or ACK for this? :)
>>
>> 20.08.2015 18:52, Guenter Roeck wrote:
>>> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
>>> is enabled. This fixes a problem seen when running a Linux image since
>>> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
>>> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
>>> starting to send data, causing transmit stalls until there is an interrupt
>>> for another reason.
>>>
>>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>
> Looks right, Jean-Christophe may know more though.
Thanks, applied to the trivial-patches tree :)
/mjt
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [Qemu-devel] [PATCH] imx_serial: Generate interrupt on tx empty if enabled
@ 2015-09-16 10:28 ` Michael Tokarev
0 siblings, 0 replies; 8+ messages in thread
From: Michael Tokarev @ 2015-09-16 10:28 UTC (permalink / raw)
To: Peter Crosthwaite, Jean-Christophe Dubois
Cc: qemu-trivial, Peter Chubb, qemu-devel@nongnu.org Developers,
Guenter Roeck
13.09.2015 23:17, Peter Crosthwaite wrote:
> On Fri, Sep 11, 2015 at 12:37 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>>
>> Can we please have some r-b or ACK for this? :)
>>
>> 20.08.2015 18:52, Guenter Roeck wrote:
>>> Generate an interrupt if the tx buffer is empty and the tx empty interrupt
>>> is enabled. This fixes a problem seen when running a Linux image since
>>> Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
>>> from imx_start_tx()"). Linux now waits for the tx empty interrupt before
>>> starting to send data, causing transmit stalls until there is an interrupt
>>> for another reason.
>>>
>>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>
> Looks right, Jean-Christophe may know more though.
Thanks, applied to the trivial-patches tree :)
/mjt
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2015-09-16 10:28 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-08-20 15:52 [Qemu-trivial] [PATCH] imx_serial: Generate interrupt on tx empty if enabled Guenter Roeck
2015-08-20 15:52 ` [Qemu-devel] " Guenter Roeck
2015-09-11 7:37 ` [Qemu-trivial] " Michael Tokarev
2015-09-11 7:37 ` [Qemu-devel] " Michael Tokarev
2015-09-13 20:17 ` [Qemu-trivial] " Peter Crosthwaite
2015-09-13 20:17 ` Peter Crosthwaite
2015-09-16 10:28 ` [Qemu-trivial] " Michael Tokarev
2015-09-16 10:28 ` [Qemu-devel] " Michael Tokarev
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.