Hi Stefan,
On lun., août 29 2016, Stefan Roese <sr@xxxxxxx> wrote:
> Hi Gregory,
>
> On 29.08.2016 16:02, Gregory CLEMENT wrote:
>> On lun., août 29 2016, Andrew Lunn <andrew@xxxxxxx> wrote:
>>
>>> On Mon, Aug 29, 2016 at 01:04:55PM +0200, Stefan Roese wrote:
>>>> This patch provides a stub function for mvebu_mbus_get_io_win_info(),
>>>> which will be used for all non-Orion (ARM32 MVEBU) platforms for
>>>> compile test coverage.
>>>>
>>>> Signed-off-by: Stefan Roese <sr@xxxxxxx>
>>>> Cc: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
>>>> Cc: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
>>>> Cc: Marcin Wojtas <mw@xxxxxxxxxxxx>
>>>> Cc: Arnd Bergmann <arnd@xxxxxxxx>
>>>> Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
>>>> ---
>>>> include/linux/mbus.h | 9 +++++++--
>>>> 1 file changed, 7 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/include/linux/mbus.h b/include/linux/mbus.h
>>>> index d610232..a884405 100644
>>>> --- a/include/linux/mbus.h
>>>> +++ b/include/linux/mbus.h
>>>> @@ -55,6 +55,8 @@ struct mbus_dram_target_info
>>>> #ifdef CONFIG_PLAT_ORION
>>>> extern const struct mbus_dram_target_info *mv_mbus_dram_info(void);
>>>> extern const struct mbus_dram_target_info *mv_mbus_dram_info_nooverlap(void);
>>>> +int mvebu_mbus_get_io_win_info(phys_addr_t phyaddr, u32 *size, u8 *target,
>>>> + u8 *attr);
>>>> #else
>>>> static inline const struct mbus_dram_target_info *mv_mbus_dram_info(void)
>>>> {
>>>> @@ -64,14 +66,17 @@ static inline const struct mbus_dram_target_info *mv_mbus_dram_info_nooverlap(vo
>>>> {
>>>> return NULL;
>>>> }
>>>> +static inline int mvebu_mbus_get_io_win_info(phys_addr_t phyaddr, u32 *size,
>>>> + u8 *target, u8 *attr)
>>>> +{
>>>> + return 0;
>>>> +}
>>>> #endif
>>>
>>> Hi Stefan
>>>
>>> If i understand it correctly, this should never be used for real, it
>>> is here only for compile testing?
>>>
>>> Maybe add a WARN_ON_ONCE(1) here? And a comment, why it should never
>>> happen.
>>
>> Actually arm64 mvebu SoC such as the Armada 3700 do not have mbus bus
>> but can still reuse the same driver than the other mvebu SoC. So in
>> this case I would prefer that the function return an error.
>
> I missed thinking about Armada 3700 while adding this IO (PCIe) support
> to the XOR DMA driver. Most likely because the Armada 3700 support was
> added after I started working on this IO (non SDRAM) DMA support for
> Armada XP.
>
> Its probably not possible to support these IO (PCIe) areas on Armada
> 3700 this way without any information from the MBus mapping as
> possible for the other ARM32 SoCs. So its perhaps best if I just
> disable this "feature" for Armada 3700 for now.
>
> What do you think?
My concern to return an error with mbus was not for the XOR
driver. It was the neta driver that I had in mind (which was not
converted yet).
Thanks,
Gregory
>
> Thanks,
> Stefan
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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