Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-31 Thread Linus Walleij
On Wed, Jan 30, 2013 at 3:53 AM, Chanho Min wrote: >> Anyway I just want to know we still need auto scale of poll rate. > I correct the mistake in this sentence. > Anyway I just want to know whether we still need auto scale of poll rate or > not. For the console/TTY and modem usecase I think

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-31 Thread Linus Walleij
On Wed, Jan 30, 2013 at 3:53 AM, Chanho Min chanho@lge.com wrote: Anyway I just want to know we still need auto scale of poll rate. I correct the mistake in this sentence. Anyway I just want to know whether we still need auto scale of poll rate or not. For the console/TTY and modem

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-29 Thread Chanho Min
> Anyway I just want to know we still need auto scale of poll rate. I correct the mistake in this sentence. Anyway I just want to know whether we still need auto scale of poll rate or not. Thanks Chanho -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-29 Thread Chanho Min
> Then it can use DMA polling post-wakeup? Yes, It will be switched back to DMA polling on UART IRQ. > What do you mean by "user" here? Userspace? Or > "platform data parameter"? platform data parameter > Not platform I think. Per usecase. > Are you not actually thinking about things like the

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-29 Thread Linus Walleij
On Tue, Jan 29, 2013 at 3:41 AM, Chanho Min wrote: > On Mon, Jan 28, 2013 at 5:28 PM, Linus Walleij > wrote: >> On Mon, Jan 28, 2013 at 9:15 AM, Chanho Min wrote: >>> [Russell] Well, I thought I had explained that I'd prefer to see the poll rate adjusted with the baud rate, but maybe I

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-29 Thread Linus Walleij
On Tue, Jan 29, 2013 at 3:41 AM, Chanho Min chanho@lge.com wrote: On Mon, Jan 28, 2013 at 5:28 PM, Linus Walleij linus.wall...@linaro.org wrote: On Mon, Jan 28, 2013 at 9:15 AM, Chanho Min chanho@lge.com wrote: [Russell] Well, I thought I had explained that I'd prefer to see the poll

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-29 Thread Chanho Min
Then it can use DMA polling post-wakeup? Yes, It will be switched back to DMA polling on UART IRQ. What do you mean by user here? Userspace? Or platform data parameter? platform data parameter Not platform I think. Per usecase. Are you not actually thinking about things like the above?

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-29 Thread Chanho Min
Anyway I just want to know we still need auto scale of poll rate. I correct the mistake in this sentence. Anyway I just want to know whether we still need auto scale of poll rate or not. Thanks Chanho -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-28 Thread Chanho Min
On Mon, Jan 28, 2013 at 5:28 PM, Linus Walleij wrote: > On Mon, Jan 28, 2013 at 9:15 AM, Chanho Min wrote: >> [Russell] >>>Well, I thought I had explained that I'd prefer to see the poll rate >>>adjusted with the baud rate, but maybe I wasn't explicit enough. >>>Instead, what we seem to have

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-28 Thread Linus Walleij
On Mon, Jan 28, 2013 at 9:15 AM, Chanho Min wrote: > [Russell] >>Well, I thought I had explained that I'd prefer to see the poll rate >>adjusted with the baud rate, but maybe I wasn't explicit enough. >>Instead, what we seem to have ended up with are two new entries in >>platform data (which

RE: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-28 Thread Chanho Min
>Well, I thought I had explained that I'd prefer to see the poll rate >adjusted with the baud rate, but maybe I wasn't explicit enough. >Instead, what we seem to have ended up with are two new entries in >platform data (which we're trying to get away from with DT): > >+ unsigned int

RE: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-28 Thread Chanho Min
Well, I thought I had explained that I'd prefer to see the poll rate adjusted with the baud rate, but maybe I wasn't explicit enough. Instead, what we seem to have ended up with are two new entries in platform data (which we're trying to get away from with DT): + unsigned int

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-28 Thread Linus Walleij
On Mon, Jan 28, 2013 at 9:15 AM, Chanho Min chanho@lge.com wrote: [Russell] Well, I thought I had explained that I'd prefer to see the poll rate adjusted with the baud rate, but maybe I wasn't explicit enough. Instead, what we seem to have ended up with are two new entries in platform data

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-28 Thread Chanho Min
On Mon, Jan 28, 2013 at 5:28 PM, Linus Walleij linus.wall...@linaro.org wrote: On Mon, Jan 28, 2013 at 9:15 AM, Chanho Min chanho@lge.com wrote: [Russell] Well, I thought I had explained that I'd prefer to see the poll rate adjusted with the baud rate, but maybe I wasn't explicit enough.

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-25 Thread Russell King - ARM Linux
On Fri, Jan 25, 2013 at 12:25:07PM -0800, Greg Kroah-Hartman wrote: > On Wed, Jan 23, 2013 at 02:07:57PM +0900, Chanho Min wrote: > > On Tue, Jan 22, 2013 at 10:18 PM, Linus Walleij > > wrote: > > >> - If poll timer is activated, We use consistent DMA mappings to avoid > > >> from > > >> the

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-25 Thread Greg Kroah-Hartman
On Wed, Jan 23, 2013 at 02:07:57PM +0900, Chanho Min wrote: > On Tue, Jan 22, 2013 at 10:18 PM, Linus Walleij > wrote: > >> - If poll timer is activated, We use consistent DMA mappings to avoid from > >> the frequent cache operation of the timer function. sg->coherency is used > >> to check

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-25 Thread Greg Kroah-Hartman
On Wed, Jan 23, 2013 at 02:07:57PM +0900, Chanho Min wrote: On Tue, Jan 22, 2013 at 10:18 PM, Linus Walleij linus.wall...@linaro.org wrote: - If poll timer is activated, We use consistent DMA mappings to avoid from the frequent cache operation of the timer function. sg-coherency is used

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-25 Thread Russell King - ARM Linux
On Fri, Jan 25, 2013 at 12:25:07PM -0800, Greg Kroah-Hartman wrote: On Wed, Jan 23, 2013 at 02:07:57PM +0900, Chanho Min wrote: On Tue, Jan 22, 2013 at 10:18 PM, Linus Walleij linus.wall...@linaro.org wrote: - If poll timer is activated, We use consistent DMA mappings to avoid from

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-22 Thread Chanho Min
On Tue, Jan 22, 2013 at 10:18 PM, Linus Walleij wrote: >> - If poll timer is activated, We use consistent DMA mappings to avoid from >> the frequent cache operation of the timer function. sg->coherency is used >> to check if buffer is coherent. > > Hm. We can begin like this but maybe we

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-22 Thread Linus Walleij
On Tue, Jan 22, 2013 at 1:45 PM, Chanho Min wrote: > In DMA support, The received data is not pushed to tty until the DMA buffer > is filled. But some megabyte rate chips such as BT expect fast response and > data should be pushed immediately. In order to fix this issue, We suggest > the use of

[PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-22 Thread Chanho Min
In DMA support, The received data is not pushed to tty until the DMA buffer is filled. But some megabyte rate chips such as BT expect fast response and data should be pushed immediately. In order to fix this issue, We suggest the use of the timer for polling DMA buffer. In our test, no data loss

[PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-22 Thread Chanho Min
In DMA support, The received data is not pushed to tty until the DMA buffer is filled. But some megabyte rate chips such as BT expect fast response and data should be pushed immediately. In order to fix this issue, We suggest the use of the timer for polling DMA buffer. In our test, no data loss

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-22 Thread Linus Walleij
On Tue, Jan 22, 2013 at 1:45 PM, Chanho Min chanho@lge.com wrote: In DMA support, The received data is not pushed to tty until the DMA buffer is filled. But some megabyte rate chips such as BT expect fast response and data should be pushed immediately. In order to fix this issue, We

Re: [PATCH v2] ARM: PL011: Add support for Rx DMA buffer polling

2013-01-22 Thread Chanho Min
On Tue, Jan 22, 2013 at 10:18 PM, Linus Walleij linus.wall...@linaro.org wrote: - If poll timer is activated, We use consistent DMA mappings to avoid from the frequent cache operation of the timer function. sg-coherency is used to check if buffer is coherent. Hm. We can begin like this