* [PATCHv5 0/2] Fix imx53-ppd UART configuration @ 2021-04-30 17:50 Sebastian Reichel 2021-04-30 17:50 ` [PATCHv5 1/2] serial: imx: Add DMA buffer configuration via DT Sebastian Reichel ` (3 more replies) 0 siblings, 4 replies; 10+ messages in thread From: Sebastian Reichel @ 2021-04-30 17:50 UTC (permalink / raw) To: Greg Kroah-Hartman, Rob Herring Cc: Jiri Slaby, Shawn Guo, Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team, Sebastian Reichel, Ian Ray, linux-kernel, linux-serial, kernel Hi, IMHO PATCHv4 was better, but in the end I don't have strong feelings about this. Btw. I think this patchset is a good demonstration of frustrating upstream kernel development can be considering PATCHv5 is basically the same as PATCHv1. Thanks for making us go in circles :( Changes since PATCHv4: * https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/ * use DT property instead of sysfs config option, like the initial patch version did as requested by Greg. Changes since PATCHv3: * https://lore.kernel.org/lkml/1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com/ * rewrote commit message to provide a lot more details why this is needed * rebased to torvalds/master (5.12-rc1-dontuse), also applies on top of linux-next * use sysfs_emit() instead of sprintf -- Sebastian Fabien Lahoudere (2): serial: imx: Add DMA buffer configuration via DT ARM: dts: imx53-ppd: add dma-info nodes .../bindings/serial/fsl-imx-uart.yaml | 12 +++++++++ arch/arm/boot/dts/imx53-ppd.dts | 2 ++ drivers/tty/serial/imx.c | 25 +++++++++++++------ 3 files changed, 32 insertions(+), 7 deletions(-) -- 2.30.2 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCHv5 1/2] serial: imx: Add DMA buffer configuration via DT 2021-04-30 17:50 [PATCHv5 0/2] Fix imx53-ppd UART configuration Sebastian Reichel @ 2021-04-30 17:50 ` Sebastian Reichel 2021-04-30 17:50 ` [PATCHv5 2/2] ARM: dts: imx53-ppd: add dma-info nodes Sebastian Reichel ` (2 subsequent siblings) 3 siblings, 0 replies; 10+ messages in thread From: Sebastian Reichel @ 2021-04-30 17:50 UTC (permalink / raw) To: Greg Kroah-Hartman, Rob Herring Cc: Jiri Slaby, Shawn Guo, Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team, Sebastian Reichel, Ian Ray, linux-kernel, linux-serial, kernel From: Fabien Lahoudere <fabien.lahoudere@collabora.com> In order to optimize serial communication (performance/throughput VS latency), we may need to tweak DMA period number and size. This adds DT properties to configure those values before initialising DMA. The defaults will stay the same as before. Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com> [update documentation and commit message, rebase to current master, switch back to DT instead of sysfs] Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> --- .../bindings/serial/fsl-imx-uart.yaml | 12 +++++++++ drivers/tty/serial/imx.c | 25 +++++++++++++------ 2 files changed, 30 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml b/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml index 2b06c6ce4a75..9d949296a142 100644 --- a/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml +++ b/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml @@ -71,6 +71,18 @@ properties: received, and that the peripheral should invert its input using the INVR registers. + fsl,dma-info: + $ref: /schemas/types.yaml#/definitions/uint32-array + minItems: 2 + maxItems: 2 + description: | + First cell contains the size of DMA buffer chunks, second cell contains + the amount of chunks used for the device. Multiplying both numbers is + the total size of memory used for receiving data. + When not being configured the system will use default settings, which + are sensible for most use cases. If you need low latency processing on + slow connections this needs to be configured appropriately. + uart-has-rtscts: true rs485-rts-delay: true diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 7d5a8dfa3e91..9e72e382a867 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -225,6 +225,8 @@ struct imx_port { struct scatterlist rx_sgl, tx_sgl[2]; void *rx_buf; struct circ_buf rx_ring; + unsigned int rx_buf_size; + unsigned int rx_period_length; unsigned int rx_periods; dma_cookie_t rx_cookie; unsigned int tx_bytes; @@ -1183,10 +1185,6 @@ static void imx_uart_dma_rx_callback(void *data) } } -/* RX DMA buffer periods */ -#define RX_DMA_PERIODS 16 -#define RX_BUF_SIZE (RX_DMA_PERIODS * PAGE_SIZE / 4) - static int imx_uart_start_rx_dma(struct imx_port *sport) { struct scatterlist *sgl = &sport->rx_sgl; @@ -1197,9 +1195,8 @@ static int imx_uart_start_rx_dma(struct imx_port *sport) sport->rx_ring.head = 0; sport->rx_ring.tail = 0; - sport->rx_periods = RX_DMA_PERIODS; - sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE); + sg_init_one(sgl, sport->rx_buf, sport->rx_buf_size); ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE); if (ret == 0) { dev_err(dev, "DMA mapping error for RX.\n"); @@ -1316,7 +1313,8 @@ static int imx_uart_dma_init(struct imx_port *sport) goto err; } - sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL); + sport->rx_buf_size = sport->rx_period_length * sport->rx_periods; + sport->rx_buf = kzalloc(sport->rx_buf_size, GFP_KERNEL); if (!sport->rx_buf) { ret = -ENOMEM; goto err; @@ -2179,11 +2177,16 @@ static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t) return HRTIMER_NORESTART; } +/* Default RX DMA buffer configuration */ +#define RX_DMA_PERIODS 16 +#define RX_DMA_PERIOD_LEN (PAGE_SIZE / 4) + static int imx_uart_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct imx_port *sport; void __iomem *base; + u32 dma_buf_conf[2]; int ret = 0; u32 ucr1; struct resource *res; @@ -2218,6 +2221,14 @@ static int imx_uart_probe(struct platform_device *pdev) if (of_get_property(np, "fsl,inverted-rx", NULL)) sport->inverted_rx = 1; + if (!of_property_read_u32_array(np, "fsl,dma-info", dma_buf_conf, 2)) { + sport->rx_period_length = dma_buf_conf[0]; + sport->rx_periods = dma_buf_conf[1]; + } else { + sport->rx_period_length = RX_DMA_PERIOD_LEN; + sport->rx_periods = RX_DMA_PERIODS; + } + if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) { dev_err(&pdev->dev, "serial%d out of range\n", sport->port.line); -- 2.30.2 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCHv5 2/2] ARM: dts: imx53-ppd: add dma-info nodes 2021-04-30 17:50 [PATCHv5 0/2] Fix imx53-ppd UART configuration Sebastian Reichel 2021-04-30 17:50 ` [PATCHv5 1/2] serial: imx: Add DMA buffer configuration via DT Sebastian Reichel @ 2021-04-30 17:50 ` Sebastian Reichel [not found] ` <YIzxKNV4x6/8GVrB@kroah.com> 2023-12-08 9:07 ` Uwe Kleine-König 3 siblings, 0 replies; 10+ messages in thread From: Sebastian Reichel @ 2021-04-30 17:50 UTC (permalink / raw) To: Greg Kroah-Hartman, Rob Herring Cc: Jiri Slaby, Shawn Guo, Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team, Sebastian Reichel, Ian Ray, linux-kernel, linux-serial, kernel From: Fabien Lahoudere <fabien.lahoudere@collabora.com> GEHC CS ONE (codename is PPD), has multiple microcontrollers connected via UART controlling. UART2 is connected to an on-board microcontroller at 19200 baud, which constantly pushes critical data (so aging character detect interrupt will never trigger). This data must be processed at 50-200 Hz, so UART should return data in less than 5-20ms. With 1024 byte DMA buffer (and a constant data stream) the read operation instead needs 1024 byte / 19200 baud = 53.333ms, which is way too long (note: Worst case would be remote processor sending data with short pauses <= 7 characters, which would further increase this number). The current downstream kernel instead configures 24 bytes resulting in 1.25ms, but that is obviously not sensible for normal UART use cases and cannot be used as new default. The same device also has another microcontroller with a 4M baud connected to UART5 exchanging lots of data. For this the same mechanism can be used to increase the buffer size (downstream uses 4K instead of the default 1K) with potentially slightly reduced buffer count. At this baud rate latency is not an issue (4096 byte / 4M baud = 0.977 ms). Before increasing the default buffer count from 4 to 16 in 76c38d30fee7, this was required to avoid data loss. With the changed default it's a performance optimization. Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com> [replace commit message] Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> --- arch/arm/boot/dts/imx53-ppd.dts | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/boot/dts/imx53-ppd.dts b/arch/arm/boot/dts/imx53-ppd.dts index be040b6a02fa..5a5fa6190a52 100644 --- a/arch/arm/boot/dts/imx53-ppd.dts +++ b/arch/arm/boot/dts/imx53-ppd.dts @@ -651,6 +651,7 @@ &uart1 { &uart2 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart2>; + fsl,dma-info = <24 20>; status = "okay"; }; @@ -670,6 +671,7 @@ &uart4 { &uart5 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart5>; + fsl,dma-info = <4096 4>; status = "okay"; }; -- 2.30.2 ^ permalink raw reply related [flat|nested] 10+ messages in thread
[parent not found: <YIzxKNV4x6/8GVrB@kroah.com>]
* Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration [not found] ` <YIzxKNV4x6/8GVrB@kroah.com> @ 2021-05-28 0:49 ` Sebastian Reichel 2021-05-28 9:03 ` Greg Kroah-Hartman 0 siblings, 1 reply; 10+ messages in thread From: Sebastian Reichel @ 2021-05-28 0:49 UTC (permalink / raw) To: Greg Kroah-Hartman; +Cc: linux-kernel, linux-serial, kernel [-- Attachment #1: Type: text/plain, Size: 2234 bytes --] Hi Greg, On Sat, May 01, 2021 at 08:11:52AM +0200, Greg Kroah-Hartman wrote: > On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: > > IMHO PATCHv4 was better, but in the end I don't have strong feelings > > about this. Btw. I think this patchset is a good demonstration of > > frustrating upstream kernel development can be considering PATCHv5 > > is basically the same as PATCHv1. Thanks for making us go in > > circles :( > > > > Changes since PATCHv4: > > * https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/ > > * use DT property instead of sysfs config option, like the initial patch > > version did as requested by Greg. > > > > Changes since PATCHv3: > > * https://lore.kernel.org/lkml/1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com/ > > * rewrote commit message to provide a lot more details why this is needed > > * rebased to torvalds/master (5.12-rc1-dontuse), also applies on top of linux-next > > * use sysfs_emit() instead of sprintf > > > > -- Sebastian > > > > Fabien Lahoudere (2): > > serial: imx: Add DMA buffer configuration via DT > > ARM: dts: imx53-ppd: add dma-info nodes > > > > .../bindings/serial/fsl-imx-uart.yaml | 12 +++++++++ > > arch/arm/boot/dts/imx53-ppd.dts | 2 ++ > > drivers/tty/serial/imx.c | 25 +++++++++++++------ > > 3 files changed, 32 insertions(+), 7 deletions(-) > > This is the friendly semi-automated patch-bot of Greg Kroah-Hartman. > You have sent him a patch that has triggered this response. > > Right now, the development tree you have sent a patch for is "closed" > due to the timing of the merge window. Don't worry, the patch(es) you > have sent are not lost, and will be looked at after the merge window is > over (after the -rc1 kernel is released by Linus). > > So thank you for your patience and your patches will be reviewed at this > later time, you do not have to do anything further, this is just a short > note to let you know the patch status and so you don't worry they didn't > make it through. > > thanks, > > greg k-h's patch email bot Any update on this? :) -- Sebastian [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration 2021-05-28 0:49 ` [PATCHv5 0/2] Fix imx53-ppd UART configuration Sebastian Reichel @ 2021-05-28 9:03 ` Greg Kroah-Hartman 2021-10-05 20:17 ` Uwe Kleine-König 0 siblings, 1 reply; 10+ messages in thread From: Greg Kroah-Hartman @ 2021-05-28 9:03 UTC (permalink / raw) To: Sebastian Reichel; +Cc: linux-kernel, linux-serial, kernel On Fri, May 28, 2021 at 02:49:52AM +0200, Sebastian Reichel wrote: > Hi Greg, > > On Sat, May 01, 2021 at 08:11:52AM +0200, Greg Kroah-Hartman wrote: > > On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: > > > IMHO PATCHv4 was better, but in the end I don't have strong feelings > > > about this. Btw. I think this patchset is a good demonstration of > > > frustrating upstream kernel development can be considering PATCHv5 > > > is basically the same as PATCHv1. Thanks for making us go in > > > circles :( > > > > > > Changes since PATCHv4: > > > * https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/ > > > * use DT property instead of sysfs config option, like the initial patch > > > version did as requested by Greg. > > > > > > Changes since PATCHv3: > > > * https://lore.kernel.org/lkml/1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com/ > > > * rewrote commit message to provide a lot more details why this is needed > > > * rebased to torvalds/master (5.12-rc1-dontuse), also applies on top of linux-next > > > * use sysfs_emit() instead of sprintf > > > > > > -- Sebastian > > > > > > Fabien Lahoudere (2): > > > serial: imx: Add DMA buffer configuration via DT > > > ARM: dts: imx53-ppd: add dma-info nodes > > > > > > .../bindings/serial/fsl-imx-uart.yaml | 12 +++++++++ > > > arch/arm/boot/dts/imx53-ppd.dts | 2 ++ > > > drivers/tty/serial/imx.c | 25 +++++++++++++------ > > > 3 files changed, 32 insertions(+), 7 deletions(-) > > > > This is the friendly semi-automated patch-bot of Greg Kroah-Hartman. > > You have sent him a patch that has triggered this response. > > > > Right now, the development tree you have sent a patch for is "closed" > > due to the timing of the merge window. Don't worry, the patch(es) you > > have sent are not lost, and will be looked at after the merge window is > > over (after the -rc1 kernel is released by Linus). > > > > So thank you for your patience and your patches will be reviewed at this > > later time, you do not have to do anything further, this is just a short > > note to let you know the patch status and so you don't worry they didn't > > make it through. > > > > thanks, > > > > greg k-h's patch email bot > > Any update on this? :) I'm waiting for the DT maintainers to review the new changes before I can take the driver changes. thanks, greg k-h ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration 2021-05-28 9:03 ` Greg Kroah-Hartman @ 2021-10-05 20:17 ` Uwe Kleine-König 0 siblings, 0 replies; 10+ messages in thread From: Uwe Kleine-König @ 2021-10-05 20:17 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Sebastian Reichel, linux-kernel, linux-serial, kernel, Rob Herring, devicetree [-- Attachment #1: Type: text/plain, Size: 3378 bytes --] Hello Greg, [adding Rob and devicetree@vger to Cc:] On Fri, May 28, 2021 at 11:03:54AM +0200, Greg Kroah-Hartman wrote: > On Fri, May 28, 2021 at 02:49:52AM +0200, Sebastian Reichel wrote: > > On Sat, May 01, 2021 at 08:11:52AM +0200, Greg Kroah-Hartman wrote: > > > On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: > > > > IMHO PATCHv4 was better, but in the end I don't have strong feelings > > > > about this. Btw. I think this patchset is a good demonstration of > > > > frustrating upstream kernel development can be considering PATCHv5 > > > > is basically the same as PATCHv1. Thanks for making us go in > > > > circles :( I was the one who objected the v1 approach. My frustration is that I wasn't Cc:d in the later iterations of this patch set. And I also liked v4 better :-\ > > > > Changes since PATCHv4: > > > > * https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/ > > > > * use DT property instead of sysfs config option, like the initial patch > > > > version did as requested by Greg. > > > > > > > > Changes since PATCHv3: > > > > * https://lore.kernel.org/lkml/1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com/ > > > > * rewrote commit message to provide a lot more details why this is needed > > > > * rebased to torvalds/master (5.12-rc1-dontuse), also applies on top of linux-next > > > > * use sysfs_emit() instead of sprintf > > > > > > > > -- Sebastian > > > > > > > > Fabien Lahoudere (2): > > > > serial: imx: Add DMA buffer configuration via DT > > > > ARM: dts: imx53-ppd: add dma-info nodes > > > > > > > > .../bindings/serial/fsl-imx-uart.yaml | 12 +++++++++ > > > > arch/arm/boot/dts/imx53-ppd.dts | 2 ++ > > > > drivers/tty/serial/imx.c | 25 +++++++++++++------ > > > > 3 files changed, 32 insertions(+), 7 deletions(-) > > > > > > This is the friendly semi-automated patch-bot of Greg Kroah-Hartman. > > > You have sent him a patch that has triggered this response. > > > > > > Right now, the development tree you have sent a patch for is "closed" > > > due to the timing of the merge window. Don't worry, the patch(es) you > > > have sent are not lost, and will be looked at after the merge window is > > > over (after the -rc1 kernel is released by Linus). > > > > > > So thank you for your patience and your patches will be reviewed at this > > > later time, you do not have to do anything further, this is just a short > > > note to let you know the patch status and so you don't worry they didn't > > > make it through. > > > > > > thanks, > > > > > > greg k-h's patch email bot > > > > Any update on this? :) > > I'm waiting for the DT maintainers to review the new changes before I > can take the driver changes. I wonder what the DT maintainers said (and where [1]). The patch was applied (db0a196bd8ad1d6bb4b1a9e54f54c09f8dc2cc25) and I think that's wrong (as it was in v1) because fsl,dma-info isn't about hardware description but about software tuning for different use cases. Best regards Uwe [1] neither my mailbox nor lore.kernel.org know about an answer. -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration 2021-04-30 17:50 [PATCHv5 0/2] Fix imx53-ppd UART configuration Sebastian Reichel ` (2 preceding siblings ...) [not found] ` <YIzxKNV4x6/8GVrB@kroah.com> @ 2023-12-08 9:07 ` Uwe Kleine-König 2023-12-08 10:32 ` Greg Kroah-Hartman 3 siblings, 1 reply; 10+ messages in thread From: Uwe Kleine-König @ 2023-12-08 9:07 UTC (permalink / raw) To: Sebastian Reichel Cc: Greg Kroah-Hartman, Rob Herring, linux-serial, Jiri Slaby, Fabio Estevam, Sascha Hauer, linux-kernel, Ian Ray, NXP Linux Team, Pengutronix Kernel Team, kernel, Shawn Guo, Rob Herring, Krzysztof Kozlowski, Conor Dooley, devicetree [-- Attachment #1: Type: text/plain, Size: 941 bytes --] [Cc += dt maintainers] On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: > IMHO PATCHv4 was better, but in the end I don't have strong feelings > about this. Btw. I think this patchset is a good demonstration of > frustrating upstream kernel development can be considering PATCHv5 > is basically the same as PATCHv1. Thanks for making us go in > circles :( I still like v4 better than v1/v5. I'm sorry for the frustration this created on your side. I'd ask Greg to reconsider given that dt is less flexible than a sysfs knob and otherwise shares all downsides of sysfs (people don't want to have to tune that, so a useful default for most cases is important; you have to consult documentation to understand how to tune it). Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration 2023-12-08 9:07 ` Uwe Kleine-König @ 2023-12-08 10:32 ` Greg Kroah-Hartman 2023-12-08 12:14 ` Krzysztof Kozlowski 0 siblings, 1 reply; 10+ messages in thread From: Greg Kroah-Hartman @ 2023-12-08 10:32 UTC (permalink / raw) To: Uwe Kleine-König Cc: Sebastian Reichel, Rob Herring, linux-serial, Jiri Slaby, Fabio Estevam, Sascha Hauer, linux-kernel, Ian Ray, NXP Linux Team, Pengutronix Kernel Team, kernel, Shawn Guo, Rob Herring, Krzysztof Kozlowski, Conor Dooley, devicetree On Fri, Dec 08, 2023 at 10:07:54AM +0100, Uwe Kleine-König wrote: > [Cc += dt maintainers] > > On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: You are responding to a message from 2021??? I can't remember what I wrote in an email last week, let alone years ago, are you sure any of this is relevant still? thanks, greg k-h ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration 2023-12-08 10:32 ` Greg Kroah-Hartman @ 2023-12-08 12:14 ` Krzysztof Kozlowski 2023-12-14 12:49 ` EXT: " Ian Ray 0 siblings, 1 reply; 10+ messages in thread From: Krzysztof Kozlowski @ 2023-12-08 12:14 UTC (permalink / raw) To: Greg Kroah-Hartman, Uwe Kleine-König Cc: Sebastian Reichel, Rob Herring, linux-serial, Jiri Slaby, Fabio Estevam, Sascha Hauer, linux-kernel, Ian Ray, NXP Linux Team, Pengutronix Kernel Team, kernel, Shawn Guo, Rob Herring, Krzysztof Kozlowski, Conor Dooley, devicetree On 08/12/2023 11:32, Greg Kroah-Hartman wrote: > On Fri, Dec 08, 2023 at 10:07:54AM +0100, Uwe Kleine-König wrote: >> [Cc += dt maintainers] >> >> On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: > > You are responding to a message from 2021??? > > I can't remember what I wrote in an email last week, let alone years > ago, are you sure any of this is relevant still? > Also, adding DT maintainers as Cc, does not magically allow us to understand the discussion. Please shortly summarize what do you need/expect from us. Best regards, Krzysztof ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: EXT: Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration 2023-12-08 12:14 ` Krzysztof Kozlowski @ 2023-12-14 12:49 ` Ian Ray 0 siblings, 0 replies; 10+ messages in thread From: Ian Ray @ 2023-12-14 12:49 UTC (permalink / raw) To: Krzysztof Kozlowski Cc: Greg Kroah-Hartman, Uwe Kleine-K??nig, Sebastian Reichel, Rob Herring, linux-serial, Jiri Slaby, Fabio Estevam, Sascha Hauer, linux-kernel, NXP Linux Team, Pengutronix Kernel Team, kernel, Shawn Guo, Rob Herring, Krzysztof Kozlowski, Conor Dooley, devicetree, nandor.han On Fri, Dec 08, 2023 at 01:14:50PM +0100, Krzysztof Kozlowski wrote: > > On 08/12/2023 11:32, Greg Kroah-Hartman wrote: > > On Fri, Dec 08, 2023 at 10:07:54AM +0100, Uwe Kleine-K??nig wrote: > >> [Cc += dt maintainers] > >> > >> On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote: > > > > You are responding to a message from 2021??? > > > > I can't remember what I wrote in an email last week, let alone years > > ago, are you sure any of this is relevant still? > > > > Also, adding DT maintainers as Cc, does not magically allow us to > understand the discussion. Please shortly summarize what do you > need/expect from us. This thread is indeed old, but we are remain interested in getting this resolved. The topic itself is about the tuning of DMA buffers for the i.MX53 platform. DMA is required (for the 4M baud UART case), and a specific buffer configuration is required, too. Two approaches have been attempted: "V4" sysfs https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/ "V5" DT https://lore.kernel.org/lkml/20210430175038.103226-1-sebastian.reichel@collabora.com/ (this thread) Uwe recently commented to [1], and (hoping to avoid any further confusion) let's continue in that thread. [1] https://lore.kernel.org/lkml/20231208090205.ioc76sych3snjiwb@pengutronix.de/ > > Best regards, > Krzysztof > > ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2023-12-14 13:26 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-04-30 17:50 [PATCHv5 0/2] Fix imx53-ppd UART configuration Sebastian Reichel 2021-04-30 17:50 ` [PATCHv5 1/2] serial: imx: Add DMA buffer configuration via DT Sebastian Reichel 2021-04-30 17:50 ` [PATCHv5 2/2] ARM: dts: imx53-ppd: add dma-info nodes Sebastian Reichel [not found] ` <YIzxKNV4x6/8GVrB@kroah.com> 2021-05-28 0:49 ` [PATCHv5 0/2] Fix imx53-ppd UART configuration Sebastian Reichel 2021-05-28 9:03 ` Greg Kroah-Hartman 2021-10-05 20:17 ` Uwe Kleine-König 2023-12-08 9:07 ` Uwe Kleine-König 2023-12-08 10:32 ` Greg Kroah-Hartman 2023-12-08 12:14 ` Krzysztof Kozlowski 2023-12-14 12:49 ` EXT: " Ian Ray
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