Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-03-07 Thread Peter Hurley
On 02/24/2016 07:37 AM, Sekhar Nori wrote: > On Wednesday 24 February 2016 08:50 AM, Peter Hurley wrote: >> Just to follow-up on what Sebastian wrote. >> >> As he pointed out, these spurious interrupts are not timeout interrupts. >> Since IIR_UART[0] == 1, no uart interrupt is pending. >> >> As he

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-03-07 Thread Peter Hurley
On 02/24/2016 07:37 AM, Sekhar Nori wrote: > On Wednesday 24 February 2016 08:50 AM, Peter Hurley wrote: >> Just to follow-up on what Sebastian wrote. >> >> As he pointed out, these spurious interrupts are not timeout interrupts. >> Since IIR_UART[0] == 1, no uart interrupt is pending. >> >> As he

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-24 Thread Sebastian Andrzej Siewior
On 02/24/2016 04:37 PM, Sekhar Nori wrote: > I don't see the error interrupt count in /proc/interrupts go up although > the code is returning IRQ_NONE when this happens. I initially thought > that must be because of the interrupt being IRQF_SHARED. But getting rid > of IRQF_SHARED still does not

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-24 Thread Sebastian Andrzej Siewior
On 02/24/2016 04:37 PM, Sekhar Nori wrote: > I don't see the error interrupt count in /proc/interrupts go up although > the code is returning IRQ_NONE when this happens. I initially thought > that must be because of the interrupt being IRQF_SHARED. But getting rid > of IRQF_SHARED still does not

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-24 Thread Sekhar Nori
On Wednesday 24 February 2016 08:50 AM, Peter Hurley wrote: > Just to follow-up on what Sebastian wrote. > > As he pointed out, these spurious interrupts are not timeout interrupts. > Since IIR_UART[0] == 1, no uart interrupt is pending. > > As he wrote, these count as spurious interrupts and

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-24 Thread Sekhar Nori
On Wednesday 24 February 2016 08:50 AM, Peter Hurley wrote: > Just to follow-up on what Sebastian wrote. > > As he pointed out, these spurious interrupts are not timeout interrupts. > Since IIR_UART[0] == 1, no uart interrupt is pending. > > As he wrote, these count as spurious interrupts and

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Peter Hurley
On 02/23/2016 01:59 AM, Sekhar Nori wrote: > On Monday 22 February 2016 09:00 PM, John Ogness wrote: >> Hi Tony, >> >> On 2016-02-11, Tony Lindgren wrote: At these speeds, nearly every DMA interrupt is accompanied by a spurious UART interrupt. So, sadly, the interrupts

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Peter Hurley
On 02/23/2016 01:59 AM, Sekhar Nori wrote: > On Monday 22 February 2016 09:00 PM, John Ogness wrote: >> Hi Tony, >> >> On 2016-02-11, Tony Lindgren wrote: At these speeds, nearly every DMA interrupt is accompanied by a spurious UART interrupt. So, sadly, the interrupts are doubled.

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Andy Shevchenko
On Tue, Feb 23, 2016 at 2:43 PM, Sebastian Andrzej Siewior wrote: > On 02/23/2016 10:59 AM, Sekhar Nori wrote: >>> With the am335x (Beaglebone Black, eDMA engine) I see 1000 DMA >>> interrupts and 1000 spurious UART interrupts. The spurious UART >>> interrupts arrive

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Andy Shevchenko
On Tue, Feb 23, 2016 at 2:43 PM, Sebastian Andrzej Siewior wrote: > On 02/23/2016 10:59 AM, Sekhar Nori wrote: >>> With the am335x (Beaglebone Black, eDMA engine) I see 1000 DMA >>> interrupts and 1000 spurious UART interrupts. The spurious UART >>> interrupts arrive 30-50us _before_ the DMA

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Sebastian Andrzej Siewior
On 02/23/2016 10:59 AM, Sekhar Nori wrote: >> With the am335x (Beaglebone Black, eDMA engine) I see 1000 DMA >> interrupts and 1000 spurious UART interrupts. The spurious UART >> interrupts arrive 30-50us _before_ the DMA interrupts. Always. >> >> If I disable UART timeout interrupts (RDI), the

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Sebastian Andrzej Siewior
On 02/23/2016 10:59 AM, Sekhar Nori wrote: >> With the am335x (Beaglebone Black, eDMA engine) I see 1000 DMA >> interrupts and 1000 spurious UART interrupts. The spurious UART >> interrupts arrive 30-50us _before_ the DMA interrupts. Always. >> >> If I disable UART timeout interrupts (RDI), the

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Sekhar Nori
On Monday 22 February 2016 09:00 PM, John Ogness wrote: > Hi Tony, > > On 2016-02-11, Tony Lindgren wrote: >>> At these speeds, nearly every DMA interrupt is accompanied by a >>> spurious UART interrupt. So, sadly, the interrupts are doubled. >>> >>> It is on my TODO list to

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-23 Thread Sekhar Nori
On Monday 22 February 2016 09:00 PM, John Ogness wrote: > Hi Tony, > > On 2016-02-11, Tony Lindgren wrote: >>> At these speeds, nearly every DMA interrupt is accompanied by a >>> spurious UART interrupt. So, sadly, the interrupts are doubled. >>> >>> It is on my TODO list to verify if the

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-22 Thread Tony Lindgren
* John Ogness [160222 07:30]: > Hi Tony, > > On 2016-02-11, Tony Lindgren wrote: > >> At these speeds, nearly every DMA interrupt is accompanied by a > >> spurious UART interrupt. So, sadly, the interrupts are doubled. > >> > >> It is on my TODO

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-22 Thread Tony Lindgren
* John Ogness [160222 07:30]: > Hi Tony, > > On 2016-02-11, Tony Lindgren wrote: > >> At these speeds, nearly every DMA interrupt is accompanied by a > >> spurious UART interrupt. So, sadly, the interrupts are doubled. > >> > >> It is on my TODO list to verify if the spurious UART interrupts >

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-22 Thread John Ogness
Hi Tony, On 2016-02-11, Tony Lindgren wrote: >> At these speeds, nearly every DMA interrupt is accompanied by a >> spurious UART interrupt. So, sadly, the interrupts are doubled. >> >> It is on my TODO list to verify if the spurious UART interrupts >> exactly match the

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-22 Thread John Ogness
Hi Tony, On 2016-02-11, Tony Lindgren wrote: >> At these speeds, nearly every DMA interrupt is accompanied by a >> spurious UART interrupt. So, sadly, the interrupts are doubled. >> >> It is on my TODO list to verify if the spurious UART interrupts >> exactly match the recently added [0]

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-11 Thread Tony Lindgren
Hi, * John Ogness [160211 04:04]: > > At these speeds, nearly every DMA interrupt is accompanied by a spurious > UART interrupt. So, sadly, the interrupts are doubled. > > It is on my TODO list to verify if the spurious UART interrupts exactly > match the recently added [0] spurious interrupt

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-11 Thread John Ogness
On 2016-02-03, Peter Hurley wrote: The DMA-enabled OMAP UART driver in its current form queues 48 bytes for a DMA-RX transfer. After the transfer is complete, a new transfer of 48 bytes is queued. The DMA completion callback runs in tasklet context, so a reschedule with

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-11 Thread John Ogness
On 2016-02-03, Peter Hurley wrote: The DMA-enabled OMAP UART driver in its current form queues 48 bytes for a DMA-RX transfer. After the transfer is complete, a new transfer of 48 bytes is queued. The DMA completion callback runs in tasklet context,

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-11 Thread Tony Lindgren
Hi, * John Ogness [160211 04:04]: > > At these speeds, nearly every DMA interrupt is accompanied by a spurious > UART interrupt. So, sadly, the interrupts are doubled. > > It is on my TODO list to verify if the spurious UART interrupts exactly > match the recently

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-02 Thread Peter Hurley
On 01/29/2016 08:35 AM, John Ogness wrote: > Hi Peter, > > On 2016-01-25, Peter Hurley wrote: >>> The DMA-enabled OMAP UART driver in its current form queues 48 bytes >>> for a DMA-RX transfer. After the transfer is complete, a new transfer >>> of 48 bytes is queued. The DMA completion callback

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-02-02 Thread Peter Hurley
On 01/29/2016 08:35 AM, John Ogness wrote: > Hi Peter, > > On 2016-01-25, Peter Hurley wrote: >>> The DMA-enabled OMAP UART driver in its current form queues 48 bytes >>> for a DMA-RX transfer. After the transfer is complete, a new transfer >>> of 48 bytes is queued.

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-01-29 Thread John Ogness
Hi Peter, On 2016-01-25, Peter Hurley wrote: >> The DMA-enabled OMAP UART driver in its current form queues 48 bytes >> for a DMA-RX transfer. After the transfer is complete, a new transfer >> of 48 bytes is queued. The DMA completion callback runs in tasklet >> context, so a reschedule with

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-01-29 Thread John Ogness
Hi Peter, On 2016-01-25, Peter Hurley wrote: >> The DMA-enabled OMAP UART driver in its current form queues 48 bytes >> for a DMA-RX transfer. After the transfer is complete, a new transfer >> of 48 bytes is queued. The DMA completion callback runs in tasklet >>

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-01-25 Thread Peter Hurley
On 01/22/2016 02:27 AM, John Ogness wrote: > The DMA-enabled OMAP UART driver in its current form queues 48 bytes for a > DMA-RX transfer. After the transfer is complete, a new transfer of 48 bytes > is queued. The DMA completion callback runs in tasklet context, so a > reschedule with context

Re: [PATCH 0/4] serial: omap: robustify for high speed transfers

2016-01-25 Thread Peter Hurley
On 01/22/2016 02:27 AM, John Ogness wrote: > The DMA-enabled OMAP UART driver in its current form queues 48 bytes for a > DMA-RX transfer. After the transfer is complete, a new transfer of 48 bytes > is queued. The DMA completion callback runs in tasklet context, so a > reschedule with context

[PATCH 0/4] serial: omap: robustify for high speed transfers

2016-01-22 Thread John Ogness
The DMA-enabled OMAP UART driver in its current form queues 48 bytes for a DMA-RX transfer. After the transfer is complete, a new transfer of 48 bytes is queued. The DMA completion callback runs in tasklet context, so a reschedule with context switch is required for the completion to be processed

[PATCH 0/4] serial: omap: robustify for high speed transfers

2016-01-22 Thread John Ogness
The DMA-enabled OMAP UART driver in its current form queues 48 bytes for a DMA-RX transfer. After the transfer is complete, a new transfer of 48 bytes is queued. The DMA completion callback runs in tasklet context, so a reschedule with context switch is required for the completion to be processed