[PATCH V2] spi: Update speed/mode on change

[Marek Vasut]

On 7/2/21 7:24 PM, Da Xue wrote:
> Hi Marek,
> 
> This patch breaks meson_spifc:
> 
> SF: Detected gd25lq128 with page size 256 Bytes, erase size 64 KiB, total
> 16 MiB
> meson_spifc spi at 8c80: Cannot set mode (err=-19)
> Failed to initialize SPI flash at 0:0 (error -19)
> 
> Best,
> 
> Da
> 
> On Wed, Jun 30, 2021 at 12:49 PM Tom Rini <trini at konsulko.com> wrote:
> 
>> On Thu, Jun 10, 2021 at 02:00:00PM +0200, Marek Vasut wrote:
>>
>>> The spi_get_bus_and_cs() may be called on the same bus and chipselect
>>> with different frequency or mode. This is valid usecase, but the code
>>> fails to notify the controller of such a configuration change. Call
>>> spi_set_speed_mode() in case bus frequency or bus mode changed to let
>>> the controller update the configuration.
>>>
>>> The problem can easily be triggered using the sspi command:
>>> => sspi 0:0 at 1000
>>> => sspi 0:0 at 2000
>>> Without this patch, both transfers happen at 1000 Hz. With this patch,
>>> the later transfer happens correctly at 2000 Hz.
>>>
>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>> Cc: Jagan Teki <jagan at amarulasolutions.com>
>>> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
>>
>> Applied to u-boot/master, thanks!
>>
>> --
>> Tom

Seems like you're hitting this code in drivers/spi/meson_spifc.c

250 static int meson_spifc_set_mode(struct udevice *dev, uint mode)
251 {
252         struct meson_spifc_priv *spifc = dev_get_priv(dev);
253
254         if (mode & (SPI_CPHA | SPI_RX_QUAD | SPI_RX_DUAL |
255                     SPI_TX_QUAD | SPI_TX_DUAL))
256                 return -ENODEV;

(the -ENODEV code doesn't look right, it should be some -EOPNOTSUP or so)

Can you check which of the mode bits is set and triggers the condition ?

I think you might be missing something like
spi-rx-bus-width = <1>;
spi-tx-bus-width = <1>;
in your DT, but that's a guess.