mbox series

[net-next,v13,00/15] stmmac: Add Loongson platform support

Message ID cover.1716973237.git.siyanteng@loongson.cn (mailing list archive)
Headers show
Series stmmac: Add Loongson platform support | expand

Message

Yanteng Si May 29, 2024, 10:17 a.m. UTC
v13:

* Sorry, we have clarified some things in the past 10 days. I did not
 give you a clear reply to the following questions in v12, so I need
 to reply again:

 1. The current LS2K2000 also have a GMAC(and two GNET) that supports 8
    channels, so we have to reconsider the initialization of
    tx/rx_queues_to_use into probe();

 2. In v12, we disagreed on the loongson_dwmac_msi_config method, but I changed
    it based on Serge's comments(If I understand correctly):
	if (dev_of_node(&pdev->dev)) {
		ret = loongson_dwmac_dt_config(pdev, plat, &res);
	}

	if (ld->loongson_id == DWMAC_CORE_LS2K2000) {
		ret = loongson_dwmac_msi_config(pdev, plat, &res);
	} else {
		ret = loongson_dwmac_intx_config(pdev, plat, &res);
	}

 3. Our priv->dma_cap.pcs is false, so let's use PHY_INTERFACE_MODE_NA;

 4. Our GMAC does not support Delay, so let's use PHY_INTERFACE_MODE_RGMII_ID,
    the current dts is wrong, a fix patch will be sent to the LoongArch list
    later.

Others:
* Re-split a part of the patch (it seems we do this with every version);
* Copied Serge's comments into the commit message of patch;
* Fixed the stmmac_dma_operation_mode() method;
* Changed some code comments.

v12:
* The biggest change is the re-splitting of patches.
* Add a "gmac_version" in loongson_data, then we only
  read it once in the _probe().
* Drop Serge's patch.
* Rebase to the latest code state.
* Fixed the gnet commit message.

v11:
* Break loongson_phylink_get_caps(), fix bad logic.
* Remove a unnecessary ";".
* Remove some unnecessary "{}".
* add a blank.
* Move the code of fix _force_1000 to patch 6/6.

The main changes occur in these two functions:
loongson_dwmac_probe();
loongson_dwmac_setup();

v10:
As Andrew's comment:
* Add a #define for the 0x37.
* Add a #define for Port Select.

others:
* Pick Serge's patch, This patch resulted from the process
  of reviewing our patch set.
* Based on Serge's patch, modify our loongson_phylink_get_caps().
* Drop patch 3/6, we need mac_interface.
* Adjusted the code layout of gnet patch.
* Corrected several errata in commit message.
* Move DISABLE_FORCE flag to loongson_gnet_data().

v9:
We have not provided a detailed list of equipment for a long time,
and I apologize for this. During this period, I have collected some
information and now present it to you, hoping to alleviate the pressure
of review.

1. IP core
We now have two types of IP cores, one is 0x37, similar to dwmac1000;
The other is 0x10.  Compared to 0x37, we split several DMA registers
from one to two, and it is not worth adding a new entry for this.
According to Serge's comment, we made these devices work by overwriting
priv->synopsys_id = 0x37 and mac->dma = <LS_dma_ops>.

1.1.  Some more detailed information
The number of DMA channels for 0x37 is 1; The number of DMA channels
for 0x10 is 8.  Except for channel 0, otherchannels do not support
sending hardware checksums. Supported AV features are Qav, Qat, and Qas,
and the rest are consistent with 3.73.

2. DEVICE
We have two types of devices,
one is GMAC, which only has a MAC chip inside and needs an external PHY
chip;
the other is GNET, which integrates both MAC and PHY chips inside.

2.1.  Some more detailed information
GMAC device: LS7A1000, LS2K1000, these devices do not support any pause
mode.
gnet device: LS7A2000, LS2K2000, the chip connection between the mac and
             phy of these devices is not normal and requires two rounds of
             negotiation; LS7A2000 does not support half-duplex and
multi-channel;
             to enable multi-channel on LS2K2000, you need to turn off
hardware checksum.
**Note**: Only the LS2K2000's IP core is 0x10, while the IP cores of other
devices are 0x37.

3. TABLE

device    type    pci_id    ip_core
ls7a1000  gmac    7a03      0x35/0x37
ls2k1000  gmac    7a03      0x35/0x37
ls7a2000  gnet    7a13      0x37
ls2k2000  gnet    7a13      0x10
-----------------------------------------------
Changes:

* passed the CI
  <https://github.com/linux-netdev/nipa/blob/main/tests/patch/checkpatch
  /checkpatch.sh>
* reverse xmas tree order.
* Silence build warning.
* Re-split the patch.
* Add more detailed commit message.
* Add more code comment.
* Reduce modification of generic code.
* using the GNET-specific prefix.
* define a new macro for the GNET MAC.
* Use an easier way to overwrite mac.
* Removed some useless printk.


v8:
* The biggest change is according to Serge's comment in the previous
  edition:
   Seeing the patch in the current state would overcomplicate the generic
   code and the only functions you need to update are
   dwmac_dma_interrupt()
   dwmac1000_dma_init_channel()
   you can have these methods re-defined with all the Loongson GNET
   specifics in the low-level platform driver (dwmac-loongson.c). After
   that you can just override the mac_device_info.dma pointer with a
   fixed stmmac_dma_ops descriptor. Here is what should be done for that:

   1. Keep the Patch 4/9 with my comments fixed. First it will be partly
   useful for your GNET device. Second in general it's a correct
   implementation of the normal DW GMAC v3.x multi-channels feature and
   will be useful for the DW GMACs with that feature enabled.

   2. Create the Loongson GNET-specific
   stmmac_dma_ops.dma_interrupt()
   stmmac_dma_ops.init_chan()
   methods in the dwmac-loongson.c driver. Don't forget to move all the
   Loongson-specific macros from dwmac_dma.h to dwmac-loongson.c.

   3. Create a Loongson GNET-specific platform setup method with the next
   semantics:
      + allocate stmmac_dma_ops instance and initialize it with
        dwmac1000_dma_ops.
      + override the stmmac_dma_ops.{dma_interrupt, init_chan} with
        the pointers to the methods defined in 2.
      + allocate mac_device_info instance and initialize the
        mac_device_info.dma field with a pointer to the new
        stmmac_dma_ops instance.
      + call dwmac1000_setup() or initialize mac_device_info in a way
        it's done in dwmac1000_setup() (the later might be better so you
        wouldn't need to export the dwmac1000_setup() function).
      + override stmmac_priv.synopsys_id with a correct value.

   4. Initialize plat_stmmacenet_data.setup() with the pointer to the
   method created in 3.

* Others:
  Re-split the patch.
  Passed checkpatch.pl test.

v7:
* Refer to andrew's suggestion:
  - Add DMA_INTR_ENA_NIE_RX and DMA_INTR_ENA_NIE_TX #define's, etc.

* Others:
  - Using --subject-prefix="PATCH net-next vN" to indicate that the
    patches are for the networking tree.
  - Rebase to the latest networking tree:
    <git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git>


v6:

* Refer to Serge's suggestion:
  - Add new platform feature flag:
    include/linux/stmmac.h:
    +#define STMMAC_FLAG_HAS_LGMAC			BIT(13)

  - Add the IRQs macros specific to the Loongson Multi-channels GMAC:
     drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h:
     +#define DMA_INTR_ENA_NIE_LOONGSON 0x00060000      /* ...*/
     #define DMA_INTR_ENA_NIE 0x00010000	/* Normal Summary */
     ...

  - Drop all of redundant changes that don't require the
    prototypes being converted to accepting the stmmac_priv
    pointer.

* Refer to andrew's suggestion:
  - Drop white space changes.
  - break patch up into lots of smaller parts.
     Some small patches have been put into another series as a preparation
     see <https://lore.kernel.org/loongarch/cover.1702289232.git.siyanteng@loongson.cn/T/#t>
     
     *note* : This series of patches relies on the three small patches above.
* others
  - Drop irq_flags changes.
  - Changed patch order.


v4 -> v5:

* Remove an ugly and useless patch (fix channel number).
* Remove the non-standard dma64 driver code, and also remove
  the HWIF entries, since the associated custom callbacks no
  longer exist.
* Refer to Serge's suggestion: Update the dwmac1000_dma.c to
  support the multi-DMA-channels controller setup.

See:
v4: <https://lore.kernel.org/loongarch/cover.1692696115.git.chenfeiyang@loongson.cn/>
v3: <https://lore.kernel.org/loongarch/cover.1691047285.git.chenfeiyang@loongson.cn/>
v2: <https://lore.kernel.org/loongarch/cover.1690439335.git.chenfeiyang@loongson.cn/>
v1: <https://lore.kernel.org/loongarch/cover.1689215889.git.chenfeiyang@loongson.cn/>

Yanteng Si (15):
  net: stmmac: Move the atds flag to the stmmac_dma_cfg structure
  net: stmmac: Add multi-channel support
  net: stmmac: Export dwmac1000_dma_ops
  net: stmmac: dwmac-loongson: Drop duplicated hash-based filter size
    init
  net: stmmac: dwmac-loongson: Use PCI_DEVICE_DATA() macro for device
    identification
  net: stmmac: dwmac-loongson: Detach GMAC-specific platform data init
  net: stmmac: dwmac-loongson: Init ref and PTP clocks rate
  net: stmmac: dwmac-loongson: Add phy_interface for Loongson GMAC
  net: stmmac: dwmac-loongson: Introduce PCI device info data
  net: stmmac: dwmac-loongson: Add DT-less GMAC PCI-device support
  net: stmmac: dwmac-loongson: Add loongson_dwmac_dt_config
  net: stmmac: Fixed failure to set network speed to 1000.
  net: stmmac: dwmac-loongson: Drop pci_enable/disable_msi temporarily
  net: stmmac: dwmac-loongson: Add Loongson GNET support
  net: stmmac: dwmac-loongson: Add loongson module author

 drivers/net/ethernet/stmicro/stmmac/common.h  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-loongson.c  | 534 ++++++++++++++++--
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c |   4 +-
 .../ethernet/stmicro/stmmac/dwmac1000_dma.c   |  35 +-
 .../ethernet/stmicro/stmmac/dwmac100_dma.c    |   2 +-
 .../net/ethernet/stmicro/stmmac/dwmac4_dma.c  |   2 +-
 .../net/ethernet/stmicro/stmmac/dwmac_dma.h   |  20 +-
 .../net/ethernet/stmicro/stmmac/dwmac_lib.c   |  30 +-
 .../ethernet/stmicro/stmmac/dwxgmac2_dma.c    |   2 +-
 drivers/net/ethernet/stmicro/stmmac/hwif.h    |   5 +-
 .../ethernet/stmicro/stmmac/stmmac_ethtool.c  |   6 +
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |  19 +-
 include/linux/stmmac.h                        |   2 +
 13 files changed, 552 insertions(+), 110 deletions(-)

Comments

Serge Semin June 5, 2024, 11:30 a.m. UTC | #1
Hi Yanteng

On Wed, May 29, 2024 at 06:17:22PM +0800, Yanteng Si wrote:
> v13:
> 
> * Sorry, we have clarified some things in the past 10 days. I did not
>  give you a clear reply to the following questions in v12, so I need
>  to reply again:
> 
>  1. The current LS2K2000 also have a GMAC(and two GNET) that supports 8
>     channels, so we have to reconsider the initialization of
>     tx/rx_queues_to_use into probe();
> 
>  2. In v12, we disagreed on the loongson_dwmac_msi_config method, but I changed
>     it based on Serge's comments(If I understand correctly):
> 	if (dev_of_node(&pdev->dev)) {
> 		ret = loongson_dwmac_dt_config(pdev, plat, &res);
> 	}
> 
> 	if (ld->loongson_id == DWMAC_CORE_LS2K2000) {
> 		ret = loongson_dwmac_msi_config(pdev, plat, &res);
> 	} else {
> 		ret = loongson_dwmac_intx_config(pdev, plat, &res);
> 	}
> 
>  3. Our priv->dma_cap.pcs is false, so let's use PHY_INTERFACE_MODE_NA;
> 
>  4. Our GMAC does not support Delay, so let's use PHY_INTERFACE_MODE_RGMII_ID,
>     the current dts is wrong, a fix patch will be sent to the LoongArch list
>     later.
> 
> Others:
> * Re-split a part of the patch (it seems we do this with every version);
> * Copied Serge's comments into the commit message of patch;
> * Fixed the stmmac_dma_operation_mode() method;
> * Changed some code comments.

Thanks for the new version of the series submitted. I've received the
copy and all the currently posted comments. Alas I'll be busy on this
week to join the discussions and start reviewing the bits. I'll be
able to do that early next week. Sorry for making you and the rest of
reviewers wait.

-Serge(y)

> 
> v12:
> * The biggest change is the re-splitting of patches.
> * Add a "gmac_version" in loongson_data, then we only
>   read it once in the _probe().
> * Drop Serge's patch.
> * Rebase to the latest code state.
> * Fixed the gnet commit message.
> 
> v11:
> * Break loongson_phylink_get_caps(), fix bad logic.
> * Remove a unnecessary ";".
> * Remove some unnecessary "{}".
> * add a blank.
> * Move the code of fix _force_1000 to patch 6/6.
> 
> The main changes occur in these two functions:
> loongson_dwmac_probe();
> loongson_dwmac_setup();
> 
> v10:
> As Andrew's comment:
> * Add a #define for the 0x37.
> * Add a #define for Port Select.
> 
> others:
> * Pick Serge's patch, This patch resulted from the process
>   of reviewing our patch set.
> * Based on Serge's patch, modify our loongson_phylink_get_caps().
> * Drop patch 3/6, we need mac_interface.
> * Adjusted the code layout of gnet patch.
> * Corrected several errata in commit message.
> * Move DISABLE_FORCE flag to loongson_gnet_data().
> 
> v9:
> We have not provided a detailed list of equipment for a long time,
> and I apologize for this. During this period, I have collected some
> information and now present it to you, hoping to alleviate the pressure
> of review.
> 
> 1. IP core
> We now have two types of IP cores, one is 0x37, similar to dwmac1000;
> The other is 0x10.  Compared to 0x37, we split several DMA registers
> from one to two, and it is not worth adding a new entry for this.
> According to Serge's comment, we made these devices work by overwriting
> priv->synopsys_id = 0x37 and mac->dma = <LS_dma_ops>.
> 
> 1.1.  Some more detailed information
> The number of DMA channels for 0x37 is 1; The number of DMA channels
> for 0x10 is 8.  Except for channel 0, otherchannels do not support
> sending hardware checksums. Supported AV features are Qav, Qat, and Qas,
> and the rest are consistent with 3.73.
> 
> 2. DEVICE
> We have two types of devices,
> one is GMAC, which only has a MAC chip inside and needs an external PHY
> chip;
> the other is GNET, which integrates both MAC and PHY chips inside.
> 
> 2.1.  Some more detailed information
> GMAC device: LS7A1000, LS2K1000, these devices do not support any pause
> mode.
> gnet device: LS7A2000, LS2K2000, the chip connection between the mac and
>              phy of these devices is not normal and requires two rounds of
>              negotiation; LS7A2000 does not support half-duplex and
> multi-channel;
>              to enable multi-channel on LS2K2000, you need to turn off
> hardware checksum.
> **Note**: Only the LS2K2000's IP core is 0x10, while the IP cores of other
> devices are 0x37.
> 
> 3. TABLE
> 
> device    type    pci_id    ip_core
> ls7a1000  gmac    7a03      0x35/0x37
> ls2k1000  gmac    7a03      0x35/0x37
> ls7a2000  gnet    7a13      0x37
> ls2k2000  gnet    7a13      0x10
> -----------------------------------------------
> Changes:
> 
> * passed the CI
>   <https://github.com/linux-netdev/nipa/blob/main/tests/patch/checkpatch
>   /checkpatch.sh>
> * reverse xmas tree order.
> * Silence build warning.
> * Re-split the patch.
> * Add more detailed commit message.
> * Add more code comment.
> * Reduce modification of generic code.
> * using the GNET-specific prefix.
> * define a new macro for the GNET MAC.
> * Use an easier way to overwrite mac.
> * Removed some useless printk.
> 
> 
> v8:
> * The biggest change is according to Serge's comment in the previous
>   edition:
>    Seeing the patch in the current state would overcomplicate the generic
>    code and the only functions you need to update are
>    dwmac_dma_interrupt()
>    dwmac1000_dma_init_channel()
>    you can have these methods re-defined with all the Loongson GNET
>    specifics in the low-level platform driver (dwmac-loongson.c). After
>    that you can just override the mac_device_info.dma pointer with a
>    fixed stmmac_dma_ops descriptor. Here is what should be done for that:
> 
>    1. Keep the Patch 4/9 with my comments fixed. First it will be partly
>    useful for your GNET device. Second in general it's a correct
>    implementation of the normal DW GMAC v3.x multi-channels feature and
>    will be useful for the DW GMACs with that feature enabled.
> 
>    2. Create the Loongson GNET-specific
>    stmmac_dma_ops.dma_interrupt()
>    stmmac_dma_ops.init_chan()
>    methods in the dwmac-loongson.c driver. Don't forget to move all the
>    Loongson-specific macros from dwmac_dma.h to dwmac-loongson.c.
> 
>    3. Create a Loongson GNET-specific platform setup method with the next
>    semantics:
>       + allocate stmmac_dma_ops instance and initialize it with
>         dwmac1000_dma_ops.
>       + override the stmmac_dma_ops.{dma_interrupt, init_chan} with
>         the pointers to the methods defined in 2.
>       + allocate mac_device_info instance and initialize the
>         mac_device_info.dma field with a pointer to the new
>         stmmac_dma_ops instance.
>       + call dwmac1000_setup() or initialize mac_device_info in a way
>         it's done in dwmac1000_setup() (the later might be better so you
>         wouldn't need to export the dwmac1000_setup() function).
>       + override stmmac_priv.synopsys_id with a correct value.
> 
>    4. Initialize plat_stmmacenet_data.setup() with the pointer to the
>    method created in 3.
> 
> * Others:
>   Re-split the patch.
>   Passed checkpatch.pl test.
> 
> v7:
> * Refer to andrew's suggestion:
>   - Add DMA_INTR_ENA_NIE_RX and DMA_INTR_ENA_NIE_TX #define's, etc.
> 
> * Others:
>   - Using --subject-prefix="PATCH net-next vN" to indicate that the
>     patches are for the networking tree.
>   - Rebase to the latest networking tree:
>     <git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git>
> 
> 
> v6:
> 
> * Refer to Serge's suggestion:
>   - Add new platform feature flag:
>     include/linux/stmmac.h:
>     +#define STMMAC_FLAG_HAS_LGMAC			BIT(13)
> 
>   - Add the IRQs macros specific to the Loongson Multi-channels GMAC:
>      drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h:
>      +#define DMA_INTR_ENA_NIE_LOONGSON 0x00060000      /* ...*/
>      #define DMA_INTR_ENA_NIE 0x00010000	/* Normal Summary */
>      ...
> 
>   - Drop all of redundant changes that don't require the
>     prototypes being converted to accepting the stmmac_priv
>     pointer.
> 
> * Refer to andrew's suggestion:
>   - Drop white space changes.
>   - break patch up into lots of smaller parts.
>      Some small patches have been put into another series as a preparation
>      see <https://lore.kernel.org/loongarch/cover.1702289232.git.siyanteng@loongson.cn/T/#t>
>      
>      *note* : This series of patches relies on the three small patches above.
> * others
>   - Drop irq_flags changes.
>   - Changed patch order.
> 
> 
> v4 -> v5:
> 
> * Remove an ugly and useless patch (fix channel number).
> * Remove the non-standard dma64 driver code, and also remove
>   the HWIF entries, since the associated custom callbacks no
>   longer exist.
> * Refer to Serge's suggestion: Update the dwmac1000_dma.c to
>   support the multi-DMA-channels controller setup.
> 
> See:
> v4: <https://lore.kernel.org/loongarch/cover.1692696115.git.chenfeiyang@loongson.cn/>
> v3: <https://lore.kernel.org/loongarch/cover.1691047285.git.chenfeiyang@loongson.cn/>
> v2: <https://lore.kernel.org/loongarch/cover.1690439335.git.chenfeiyang@loongson.cn/>
> v1: <https://lore.kernel.org/loongarch/cover.1689215889.git.chenfeiyang@loongson.cn/>
> 
> Yanteng Si (15):
>   net: stmmac: Move the atds flag to the stmmac_dma_cfg structure
>   net: stmmac: Add multi-channel support
>   net: stmmac: Export dwmac1000_dma_ops
>   net: stmmac: dwmac-loongson: Drop duplicated hash-based filter size
>     init
>   net: stmmac: dwmac-loongson: Use PCI_DEVICE_DATA() macro for device
>     identification
>   net: stmmac: dwmac-loongson: Detach GMAC-specific platform data init
>   net: stmmac: dwmac-loongson: Init ref and PTP clocks rate
>   net: stmmac: dwmac-loongson: Add phy_interface for Loongson GMAC
>   net: stmmac: dwmac-loongson: Introduce PCI device info data
>   net: stmmac: dwmac-loongson: Add DT-less GMAC PCI-device support
>   net: stmmac: dwmac-loongson: Add loongson_dwmac_dt_config
>   net: stmmac: Fixed failure to set network speed to 1000.
>   net: stmmac: dwmac-loongson: Drop pci_enable/disable_msi temporarily
>   net: stmmac: dwmac-loongson: Add Loongson GNET support
>   net: stmmac: dwmac-loongson: Add loongson module author
> 
>  drivers/net/ethernet/stmicro/stmmac/common.h  |   1 +
>  .../ethernet/stmicro/stmmac/dwmac-loongson.c  | 534 ++++++++++++++++--
>  .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c |   4 +-
>  .../ethernet/stmicro/stmmac/dwmac1000_dma.c   |  35 +-
>  .../ethernet/stmicro/stmmac/dwmac100_dma.c    |   2 +-
>  .../net/ethernet/stmicro/stmmac/dwmac4_dma.c  |   2 +-
>  .../net/ethernet/stmicro/stmmac/dwmac_dma.h   |  20 +-
>  .../net/ethernet/stmicro/stmmac/dwmac_lib.c   |  30 +-
>  .../ethernet/stmicro/stmmac/dwxgmac2_dma.c    |   2 +-
>  drivers/net/ethernet/stmicro/stmmac/hwif.h    |   5 +-
>  .../ethernet/stmicro/stmmac/stmmac_ethtool.c  |   6 +
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c |  19 +-
>  include/linux/stmmac.h                        |   2 +
>  13 files changed, 552 insertions(+), 110 deletions(-)
> 
> -- 
> 2.31.4
>
Yanteng Si June 6, 2024, 12:27 p.m. UTC | #2
Hi Serge,

在 2024/6/5 19:30, Serge Semin 写道:
> On Wed, May 29, 2024 at 06:17:22PM +0800, Yanteng Si wrote:
>> v13:
>>
>> * Sorry, we have clarified some things in the past 10 days. I did not
>>   give you a clear reply to the following questions in v12, so I need
>>   to reply again:
>>
>>   1. The current LS2K2000 also have a GMAC(and two GNET) that supports 8
>>      channels, so we have to reconsider the initialization of
>>      tx/rx_queues_to_use into probe();
>>
>>   2. In v12, we disagreed on the loongson_dwmac_msi_config method, but I changed
>>      it based on Serge's comments(If I understand correctly):
>> 	if (dev_of_node(&pdev->dev)) {
>> 		ret = loongson_dwmac_dt_config(pdev, plat, &res);
>> 	}
>>
>> 	if (ld->loongson_id == DWMAC_CORE_LS2K2000) {
>> 		ret = loongson_dwmac_msi_config(pdev, plat, &res);
>> 	} else {
>> 		ret = loongson_dwmac_intx_config(pdev, plat, &res);
>> 	}
>>
>>   3. Our priv->dma_cap.pcs is false, so let's use PHY_INTERFACE_MODE_NA;
>>
>>   4. Our GMAC does not support Delay, so let's use PHY_INTERFACE_MODE_RGMII_ID,
>>      the current dts is wrong, a fix patch will be sent to the LoongArch list
>>      later.
>>
>> Others:
>> * Re-split a part of the patch (it seems we do this with every version);
>> * Copied Serge's comments into the commit message of patch;
>> * Fixed the stmmac_dma_operation_mode() method;
>> * Changed some code comments.
> Thanks for the new version of the series submitted. I've received the
> copy and all the currently posted comments. Alas I'll be busy on this
> week to join the discussions and start reviewing the bits. I'll be
> able to do that early next week. Sorry for making you and the rest of
> reviewers wait.

Thanks for your reply.

Ok, I just had time to test Huacai's method.


Thanks,

Yanteng
Russell King (Oracle) June 6, 2024, 6:27 p.m. UTC | #3
On Wed, May 29, 2024 at 06:17:22PM +0800, Yanteng Si wrote:
>  3. Our priv->dma_cap.pcs is false, so let's use PHY_INTERFACE_MODE_NA;

Useful to note.

>  4. Our GMAC does not support Delay, so let's use PHY_INTERFACE_MODE_RGMII_ID,
>     the current dts is wrong, a fix patch will be sent to the LoongArch list
>     later.

RGMII requires a delay somewhere in the system, and there are three
options: at the MAC, in the board traces, or at the PHY. The
PHY_INTERFACE_MODE_RGMII* passed to the PHY determines what delays the
PHY uses, and thus what the GMAC uses has no bearing on this - if the
board traces are adding the required delay, then
PHY_INTERFACE_MODE_RGMII is sufficient.

If the board traces do not add the required delay, and the GMAC doesn't
add a delay, then it is necessary to add the delay at the PHY, so
using PHY_INTERFACE_MODE_RGMII_ID is appropriate.

It's all detailed in Documentation/networking/phy.rst

What isn't documented there (and arguably should be) is if the MAC
adjusts its delays according to the PHY interface mode, then the MAC
should pass PHY_INTERFACE_MODE_RGMII to the PHY _irrespective_ of
which _ID/_TXID/ _RXID has been selected by firmware (since we don't
want the PHY to be adding its own delays if they've already been taken
care of by the MAC.)
Andrew Lunn June 6, 2024, 6:39 p.m. UTC | #4
On Thu, Jun 06, 2024 at 07:27:52PM +0100, Russell King (Oracle) wrote:
> On Wed, May 29, 2024 at 06:17:22PM +0800, Yanteng Si wrote:
> >  3. Our priv->dma_cap.pcs is false, so let's use PHY_INTERFACE_MODE_NA;
> 
> Useful to note.
> 
> >  4. Our GMAC does not support Delay, so let's use PHY_INTERFACE_MODE_RGMII_ID,
> >     the current dts is wrong, a fix patch will be sent to the LoongArch list
> >     later.
> 
> RGMII requires a delay somewhere in the system, and there are three
> options: at the MAC, in the board traces, or at the PHY. The
> PHY_INTERFACE_MODE_RGMII* passed to the PHY determines what delays the
> PHY uses, and thus what the GMAC uses has no bearing on this - if the
> board traces are adding the required delay, then
> PHY_INTERFACE_MODE_RGMII is sufficient.
> 
> If the board traces do not add the required delay, and the GMAC doesn't
> add a delay, then it is necessary to add the delay at the PHY, so
> using PHY_INTERFACE_MODE_RGMII_ID is appropriate.
> 
> It's all detailed in Documentation/networking/phy.rst
> 
> What isn't documented there (and arguably should be) is if the MAC
> adjusts its delays according to the PHY interface mode, then the MAC
> should pass PHY_INTERFACE_MODE_RGMII to the PHY _irrespective_ of
> which _ID/_TXID/ _RXID has been selected by firmware (since we don't
> want the PHY to be adding its own delays if they've already been taken
> care of by the MAC.)

Just adding to this, the vast majority of systems default to the PHY
adding the delays. There are only a small number of systems with the
MAC adding the delays, even if many MACs have hardware to allow the
MAC to add the delays. Keeping things uniform just avoids problems, so
i always suggest the PHY should add the delay.

    Andrew