net: ethernet: ti: davinci_cpdma: fix fixed prio cpdma ctlr configuration
diff mbox

Message ID 1478610656-24634-1-git-send-email-ivan.khoronzhuk@linaro.org
State New
Headers show

Commit Message

Ivan Khoronzhuk Nov. 8, 2016, 1:10 p.m. UTC
The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr
cannot be configured after cpdma is stopped. So, restore content
of cpdma ctlr while off/on procedure.

Based on net-next/master

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
 drivers/net/ethernet/ti/cpsw.c          |   6 +-
 drivers/net/ethernet/ti/davinci_cpdma.c | 103 +++++++++++++++++---------------
 drivers/net/ethernet/ti/davinci_cpdma.h |   2 +
 3 files changed, 58 insertions(+), 53 deletions(-)

Comments

Grygorii Strashko Nov. 9, 2016, 9:09 p.m. UTC | #1
On 11/08/2016 07:10 AM, Ivan Khoronzhuk wrote:
> The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr

I assume this is because cpdma_ctlr_start() does soft reset. Is it correct?

> cannot be configured after cpdma is stopped. So, restore content
> of cpdma ctlr while off/on procedure.
> 
> Based on net-next/master

^ remove it

> 
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
> ---
>  drivers/net/ethernet/ti/cpsw.c          |   6 +-
>  drivers/net/ethernet/ti/davinci_cpdma.c | 103 +++++++++++++++++---------------
>  drivers/net/ethernet/ti/davinci_cpdma.h |   2 +
>  3 files changed, 58 insertions(+), 53 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> index b1ddf89..4d04b8e 100644
> --- a/drivers/net/ethernet/ti/cpsw.c
> +++ b/drivers/net/ethernet/ti/cpsw.c
> @@ -1376,10 +1376,6 @@ static int cpsw_ndo_open(struct net_device *ndev)
>  				  ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);
>  
>  	if (!cpsw_common_res_usage_state(cpsw)) {
> -		/* setup tx dma to fixed prio and zero offset */
> -		cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1);
> -		cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0);
> -
>  		/* disable priority elevation */
>  		__raw_writel(0, &cpsw->regs->ptype);
>  
> @@ -2710,6 +2706,8 @@ static int cpsw_probe(struct platform_device *pdev)
>  	dma_params.desc_align		= 16;
>  	dma_params.has_ext_regs		= true;
>  	dma_params.desc_hw_addr         = dma_params.desc_mem_phys;
> +	dma_params.rxbuf_offset		= 0;
> +	dma_params.fixed_prio		= 1;

Do we really need this new parameters? Do you have plans to use other values?
Ivan Khoronzhuk Nov. 9, 2016, 11:56 p.m. UTC | #2
On 09.11.16 23:09, Grygorii Strashko wrote:
>
>
> On 11/08/2016 07:10 AM, Ivan Khoronzhuk wrote:
>> The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr
>
> I assume this is because cpdma_ctlr_start() does soft reset. Is it correct?
Probably not. I've seen this register doesn't hold any previous settings (just trash)
after cpdma_ctlr_stop(), actually after last channel is stopped (inside of cpdma_ctlr_stop()).
Then cpdma_ctlr_start() just reset it to 0.

>
>> cannot be configured after cpdma is stopped. So, restore content
>> of cpdma ctlr while off/on procedure.
>>
>> Based on net-next/master
>
> ^ remove it
sure

>
>>
>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>> ---
>>  drivers/net/ethernet/ti/cpsw.c          |   6 +-
>>  drivers/net/ethernet/ti/davinci_cpdma.c | 103 +++++++++++++++++---------------
>>  drivers/net/ethernet/ti/davinci_cpdma.h |   2 +
>>  3 files changed, 58 insertions(+), 53 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
>> index b1ddf89..4d04b8e 100644
>> --- a/drivers/net/ethernet/ti/cpsw.c
>> +++ b/drivers/net/ethernet/ti/cpsw.c
>> @@ -1376,10 +1376,6 @@ static int cpsw_ndo_open(struct net_device *ndev)
>>  				  ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);
>>
>>  	if (!cpsw_common_res_usage_state(cpsw)) {
>> -		/* setup tx dma to fixed prio and zero offset */
>> -		cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1);
>> -		cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0);
>> -
>>  		/* disable priority elevation */
>>  		__raw_writel(0, &cpsw->regs->ptype);
>>
>> @@ -2710,6 +2706,8 @@ static int cpsw_probe(struct platform_device *pdev)
>>  	dma_params.desc_align		= 16;
>>  	dma_params.has_ext_regs		= true;
>>  	dma_params.desc_hw_addr         = dma_params.desc_mem_phys;
>> +	dma_params.rxbuf_offset		= 0;
>> +	dma_params.fixed_prio		= 1;
>
> Do we really need this new parameters? Do you have plans to use other values?
I'm ok if this is static (equally as a bunch of rest in dma_params), no see reason to use other values,
it at least now. But the issue is not only in these two parameters and not only in cpsw_ndo_open().
It touches cpsw_set_channels() also, where ctlr stop/start is present.
In order to not copy cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1)...
in all such kind places in eth drivers, better to allow the cpdma to control it's parameters...

The cpdma ctlr register holds a little more parameters (but only two of them are set in cpsw)
Maybe there is reason to save them also. Actually I'd seen this problem when playing with
on/off channel shapers, unfortunately the cpdma ctlr holds this info also, and it was lost
while on/off (but I'm going to restore it in chan_start()).


>
Grygorii Strashko Nov. 10, 2016, 4:37 p.m. UTC | #3
On 11/09/2016 05:56 PM, Ivan Khoronzhuk wrote:
> 
> 
> On 09.11.16 23:09, Grygorii Strashko wrote:
>>
>>
>> On 11/08/2016 07:10 AM, Ivan Khoronzhuk wrote:
>>> The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr
>>
>> I assume this is because cpdma_ctlr_start() does soft reset. Is it
>> correct?
> Probably not. I've seen this register doesn't hold any previous settings
> (just trash)

What register CPDMA_DMACONTROL or CPSW_DMACTRL?

> after cpdma_ctlr_stop(), actually after last channel is stopped (inside
> of cpdma_ctlr_stop()).

So, You are stating that Registers context is changed after stop?

> Then cpdma_ctlr_start() just reset it to 0.

"just trash" or "0".

Sry, I do not see how cpdma_ctlr_stop() can affect on registers state :(
and I'd very appreciated if can provide more detailed information.

> 
>>
>>> cannot be configured after cpdma is stopped. So, restore content
>>> of cpdma ctlr while off/on procedure.
>>>
>>> Based on net-next/master
>>
>> ^ remove it
> sure
> 
>>
>>>
>>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>>> ---
>>>  drivers/net/ethernet/ti/cpsw.c          |   6 +-
>>>  drivers/net/ethernet/ti/davinci_cpdma.c | 103
>>> +++++++++++++++++---------------
>>>  drivers/net/ethernet/ti/davinci_cpdma.h |   2 +
>>>  3 files changed, 58 insertions(+), 53 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/ti/cpsw.c
>>> b/drivers/net/ethernet/ti/cpsw.c
>>> index b1ddf89..4d04b8e 100644
>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>> @@ -1376,10 +1376,6 @@ static int cpsw_ndo_open(struct net_device *ndev)
>>>                    ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);
>>>
>>>      if (!cpsw_common_res_usage_state(cpsw)) {
>>> -        /* setup tx dma to fixed prio and zero offset */
>>> -        cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1);
>>> -        cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0);
>>> -
>>>          /* disable priority elevation */
>>>          __raw_writel(0, &cpsw->regs->ptype);
>>>
>>> @@ -2710,6 +2706,8 @@ static int cpsw_probe(struct platform_device
>>> *pdev)
>>>      dma_params.desc_align        = 16;
>>>      dma_params.has_ext_regs        = true;
>>>      dma_params.desc_hw_addr         = dma_params.desc_mem_phys;
>>> +    dma_params.rxbuf_offset        = 0;
>>> +    dma_params.fixed_prio        = 1;
>>
>> Do we really need this new parameters? Do you have plans to use other
>> values?
> I'm ok if this is static (equally as a bunch of rest in dma_params), no
> see reason to use other values,

That's what i wanted to know :) - go static, pls.

> it at least now. But the issue is not only in these two parameters and
> not only in cpsw_ndo_open().
> It touches cpsw_set_channels() also, where ctlr stop/start is present.
> In order to not copy cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED,
> 1)...
> in all such kind places in eth drivers, better to allow the cpdma to
> control it's parameters...
> 
> The cpdma ctlr register holds a little more parameters (but only two of
> them are set in cpsw)
> Maybe there is reason to save them also. Actually I'd seen this problem
> when playing with
> on/off channel shapers, unfortunately the cpdma ctlr holds this info
> also, and it was lost
> while on/off (but I'm going to restore it in chan_start()).
> 

I understand you change, but I'm note sure about real root cause :(
Ivan Khoronzhuk Nov. 10, 2016, 7:52 p.m. UTC | #4
On 10.11.16 18:37, Grygorii Strashko wrote:
>
>
> On 11/09/2016 05:56 PM, Ivan Khoronzhuk wrote:
>>
>>
>> On 09.11.16 23:09, Grygorii Strashko wrote:
>>>
>>>
>>> On 11/08/2016 07:10 AM, Ivan Khoronzhuk wrote:
>>>> The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr
>>>
>>> I assume this is because cpdma_ctlr_start() does soft reset. Is it
>>> correct?
>> Probably not. I've seen this register doesn't hold any previous settings
>> (just trash)
>
> What register CPDMA_DMACONTROL or CPSW_DMACTRL?
>
>> after cpdma_ctlr_stop(), actually after last channel is stopped (inside
>> of cpdma_ctlr_stop()).
>
> So, You are stating that Registers context is changed after stop?
>
>> Then cpdma_ctlr_start() just reset it to 0.
>
> "just trash" or "0".
>
> Sry, I do not see how cpdma_ctlr_stop() can affect on registers state :(
> and I'd very appreciated if can provide more detailed information.
>
I've checked again, it was my mistake. It simply reset to 0 while soft reset.

>>
>>>
>>>> cannot be configured after cpdma is stopped. So, restore content
>>>> of cpdma ctlr while off/on procedure.
>>>>
>>>> Based on net-next/master
>>>
>>> ^ remove it
>> sure
>>
>>>
>>>>
>>>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>>>> ---
>>>>  drivers/net/ethernet/ti/cpsw.c          |   6 +-
>>>>  drivers/net/ethernet/ti/davinci_cpdma.c | 103
>>>> +++++++++++++++++---------------
>>>>  drivers/net/ethernet/ti/davinci_cpdma.h |   2 +
>>>>  3 files changed, 58 insertions(+), 53 deletions(-)
>>>>
>>>> diff --git a/drivers/net/ethernet/ti/cpsw.c
>>>> b/drivers/net/ethernet/ti/cpsw.c
>>>> index b1ddf89..4d04b8e 100644
>>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>>> @@ -1376,10 +1376,6 @@ static int cpsw_ndo_open(struct net_device *ndev)
>>>>                    ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);
>>>>
>>>>      if (!cpsw_common_res_usage_state(cpsw)) {
>>>> -        /* setup tx dma to fixed prio and zero offset */
>>>> -        cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1);
>>>> -        cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0);
>>>> -
>>>>          /* disable priority elevation */
>>>>          __raw_writel(0, &cpsw->regs->ptype);
>>>>
>>>> @@ -2710,6 +2706,8 @@ static int cpsw_probe(struct platform_device
>>>> *pdev)
>>>>      dma_params.desc_align        = 16;
>>>>      dma_params.has_ext_regs        = true;
>>>>      dma_params.desc_hw_addr         = dma_params.desc_mem_phys;
>>>> +    dma_params.rxbuf_offset        = 0;
>>>> +    dma_params.fixed_prio        = 1;
>>>
>>> Do we really need this new parameters? Do you have plans to use other
>>> values?
>> I'm ok if this is static (equally as a bunch of rest in dma_params), no
>> see reason to use other values,
>
> That's what i wanted to know :) - go static, pls.
>
>> it at least now. But the issue is not only in these two parameters and
>> not only in cpsw_ndo_open().
>> It touches cpsw_set_channels() also, where ctlr stop/start is present.
>> In order to not copy cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED,
>> 1)...
>> in all such kind places in eth drivers, better to allow the cpdma to
>> control it's parameters...
>>
>> The cpdma ctlr register holds a little more parameters (but only two of
>> them are set in cpsw)
>> Maybe there is reason to save them also. Actually I'd seen this problem
>> when playing with
>> on/off channel shapers, unfortunately the cpdma ctlr holds this info
>> also, and it was lost
>> while on/off (but I'm going to restore it in chan_start()).
>>
>
> I understand you change, but I'm note sure about real root cause :(
so, are you Ok with current version?

>
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Grygorii Strashko Nov. 10, 2016, 10:58 p.m. UTC | #5
On 11/10/2016 01:52 PM, ivan.khoronzhuk wrote:
>
>
> On 10.11.16 18:37, Grygorii Strashko wrote:
>>
>>
>> On 11/09/2016 05:56 PM, Ivan Khoronzhuk wrote:
>>>
>>>
>>> On 09.11.16 23:09, Grygorii Strashko wrote:
>>>>
>>>>
>>>> On 11/08/2016 07:10 AM, Ivan Khoronzhuk wrote:
>>>>> The dma ctlr is reseted to 0 while cpdma start, thus cpdma ctlr
>>>>
>>>> I assume this is because cpdma_ctlr_start() does soft reset. Is it
>>>> correct?
>>> Probably not. I've seen this register doesn't hold any previous settings
>>> (just trash)
>>
>> What register CPDMA_DMACONTROL or CPSW_DMACTRL?
>>
>>> after cpdma_ctlr_stop(), actually after last channel is stopped (inside
>>> of cpdma_ctlr_stop()).
>>
>> So, You are stating that Registers context is changed after stop?
>>
>>> Then cpdma_ctlr_start() just reset it to 0.
>>
>> "just trash" or "0".
>>
>> Sry, I do not see how cpdma_ctlr_stop() can affect on registers state :(
>> and I'd very appreciated if can provide more detailed information.
>>
> I've checked again, it was my mistake. It simply reset to 0 while soft
> reset.
>
>>>
>>>>
>>>>> cannot be configured after cpdma is stopped. So, restore content
>>>>> of cpdma ctlr while off/on procedure.
>>>>>
>>>>> Based on net-next/master
>>>>
>>>> ^ remove it
>>> sure
>>>
>>>>
>>>>>
>>>>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>>>>> ---
>>>>>  drivers/net/ethernet/ti/cpsw.c          |   6 +-
>>>>>  drivers/net/ethernet/ti/davinci_cpdma.c | 103
>>>>> +++++++++++++++++---------------
>>>>>  drivers/net/ethernet/ti/davinci_cpdma.h |   2 +
>>>>>  3 files changed, 58 insertions(+), 53 deletions(-)
>>>>>
>>>>> diff --git a/drivers/net/ethernet/ti/cpsw.c
>>>>> b/drivers/net/ethernet/ti/cpsw.c
>>>>> index b1ddf89..4d04b8e 100644
>>>>> --- a/drivers/net/ethernet/ti/cpsw.c
>>>>> +++ b/drivers/net/ethernet/ti/cpsw.c
>>>>> @@ -1376,10 +1376,6 @@ static int cpsw_ndo_open(struct net_device
>>>>> *ndev)
>>>>>                    ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);
>>>>>
>>>>>      if (!cpsw_common_res_usage_state(cpsw)) {
>>>>> -        /* setup tx dma to fixed prio and zero offset */
>>>>> -        cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1);
>>>>> -        cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0);
>>>>> -
>>>>>          /* disable priority elevation */
>>>>>          __raw_writel(0, &cpsw->regs->ptype);
>>>>>
>>>>> @@ -2710,6 +2706,8 @@ static int cpsw_probe(struct platform_device
>>>>> *pdev)
>>>>>      dma_params.desc_align        = 16;
>>>>>      dma_params.has_ext_regs        = true;
>>>>>      dma_params.desc_hw_addr         = dma_params.desc_mem_phys;
>>>>> +    dma_params.rxbuf_offset        = 0;
>>>>> +    dma_params.fixed_prio        = 1;
>>>>
>>>> Do we really need this new parameters? Do you have plans to use other
>>>> values?
>>> I'm ok if this is static (equally as a bunch of rest in dma_params), no
>>> see reason to use other values,
>>
>> That's what i wanted to know :) - go static, pls.
>>
>>> it at least now. But the issue is not only in these two parameters and
>>> not only in cpsw_ndo_open().
>>> It touches cpsw_set_channels() also, where ctlr stop/start is present.
>>> In order to not copy cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED,
>>> 1)...
>>> in all such kind places in eth drivers, better to allow the cpdma to
>>> control it's parameters...
>>>
>>> The cpdma ctlr register holds a little more parameters (but only two of
>>> them are set in cpsw)
>>> Maybe there is reason to save them also. Actually I'd seen this problem
>>> when playing with
>>> on/off channel shapers, unfortunately the cpdma ctlr holds this info
>>> also, and it was lost
>>> while on/off (but I'm going to restore it in chan_start()).
>>>
>>
>> I understand you change, but I'm note sure about real root cause :(
> so, are you Ok with current version?

No. pls, use constant values and do not introduce additional parameters.
Also, pls update commit message with new information.

Patch
diff mbox

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index b1ddf89..4d04b8e 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1376,10 +1376,6 @@  static int cpsw_ndo_open(struct net_device *ndev)
 				  ALE_ALL_PORTS, ALE_ALL_PORTS, 0, 0);
 
 	if (!cpsw_common_res_usage_state(cpsw)) {
-		/* setup tx dma to fixed prio and zero offset */
-		cpdma_control_set(cpsw->dma, CPDMA_TX_PRIO_FIXED, 1);
-		cpdma_control_set(cpsw->dma, CPDMA_RX_BUFFER_OFFSET, 0);
-
 		/* disable priority elevation */
 		__raw_writel(0, &cpsw->regs->ptype);
 
@@ -2710,6 +2706,8 @@  static int cpsw_probe(struct platform_device *pdev)
 	dma_params.desc_align		= 16;
 	dma_params.has_ext_regs		= true;
 	dma_params.desc_hw_addr         = dma_params.desc_mem_phys;
+	dma_params.rxbuf_offset		= 0;
+	dma_params.fixed_prio		= 1;
 
 	cpsw->dma = cpdma_ctlr_create(&dma_params);
 	if (!cpsw->dma) {
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index c3f35f1..05afc05 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -124,6 +124,29 @@  struct cpdma_chan {
 	int	int_set, int_clear, td;
 };
 
+struct cpdma_control_info {
+	u32		reg;
+	u32		shift, mask;
+	int		access;
+#define ACCESS_RO	BIT(0)
+#define ACCESS_WO	BIT(1)
+#define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
+};
+
+static struct cpdma_control_info controls[] = {
+	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
+	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
+	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
+	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
+	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
+	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
+	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
+	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
+	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
+	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
+	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
+};
+
 #define tx_chan_num(chan)	(chan)
 #define rx_chan_num(chan)	((chan) + CPDMA_MAX_CHANNELS)
 #define is_rx_chan(chan)	((chan)->chan_num >= CPDMA_MAX_CHANNELS)
@@ -253,6 +276,31 @@  static void cpdma_desc_free(struct cpdma_desc_pool *pool,
 	gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size);
 }
 
+static int _cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
+{
+	struct cpdma_control_info *info = &controls[control];
+	u32 val;
+
+	if (!ctlr->params.has_ext_regs)
+		return -ENOTSUPP;
+
+	if (ctlr->state != CPDMA_STATE_ACTIVE)
+		return -EINVAL;
+
+	if (control < 0 || control >= ARRAY_SIZE(controls))
+		return -ENOENT;
+
+	if ((info->access & ACCESS_WO) != ACCESS_WO)
+		return -EPERM;
+
+	val  = dma_reg_read(ctlr, info->reg);
+	val &= ~(info->mask << info->shift);
+	val |= (value & info->mask) << info->shift;
+	dma_reg_write(ctlr, info->reg, val);
+
+	return 0;
+}
+
 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
 {
 	struct cpdma_ctlr *ctlr;
@@ -324,6 +372,11 @@  int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
 		if (ctlr->channels[i])
 			cpdma_chan_start(ctlr->channels[i]);
 	}
+
+	_cpdma_control_set(ctlr, CPDMA_TX_PRIO_FIXED, ctlr->params.fixed_prio);
+	_cpdma_control_set(ctlr, CPDMA_RX_BUFFER_OFFSET,
+			   ctlr->params.rxbuf_offset);
+
 	spin_unlock_irqrestore(&ctlr->lock, flags);
 	return 0;
 }
@@ -874,29 +927,6 @@  int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
 	return 0;
 }
 
-struct cpdma_control_info {
-	u32		reg;
-	u32		shift, mask;
-	int		access;
-#define ACCESS_RO	BIT(0)
-#define ACCESS_WO	BIT(1)
-#define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
-};
-
-static struct cpdma_control_info controls[] = {
-	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
-	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
-	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
-	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
-	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
-	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
-	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
-	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
-	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
-	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
-	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
-};
-
 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
 {
 	unsigned long flags;
@@ -931,35 +961,10 @@  int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
 {
 	unsigned long flags;
-	struct cpdma_control_info *info = &controls[control];
 	int ret;
-	u32 val;
 
 	spin_lock_irqsave(&ctlr->lock, flags);
-
-	ret = -ENOTSUPP;
-	if (!ctlr->params.has_ext_regs)
-		goto unlock_ret;
-
-	ret = -EINVAL;
-	if (ctlr->state != CPDMA_STATE_ACTIVE)
-		goto unlock_ret;
-
-	ret = -ENOENT;
-	if (control < 0 || control >= ARRAY_SIZE(controls))
-		goto unlock_ret;
-
-	ret = -EPERM;
-	if ((info->access & ACCESS_WO) != ACCESS_WO)
-		goto unlock_ret;
-
-	val  = dma_reg_read(ctlr, info->reg);
-	val &= ~(info->mask << info->shift);
-	val |= (value & info->mask) << info->shift;
-	dma_reg_write(ctlr, info->reg, val);
-	ret = 0;
-
-unlock_ret:
+	ret = _cpdma_control_set(ctlr, control, value);
 	spin_unlock_irqrestore(&ctlr->lock, flags);
 	return ret;
 }
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.h b/drivers/net/ethernet/ti/davinci_cpdma.h
index a07b22b..e66420f 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.h
+++ b/drivers/net/ethernet/ti/davinci_cpdma.h
@@ -31,6 +31,8 @@  struct cpdma_params {
 	void __iomem		*rxthresh, *rxfree;
 	int			num_chan;
 	bool			has_soft_reset;
+	bool			fixed_prio;
+	int			rxbuf_offset;
 	int			min_packet_size;
 	u32			desc_mem_phys;
 	u32			desc_hw_addr;