linux-toradex.git/drivers/spi, branch v6.10-rc2

spi: stm32: Don't warn about spurious interrupts

2024-05-29T18:12:09+00:00

The dev_warn to notify about a spurious interrupt was introduced with
the reasoning that these are unexpected. However spurious interrupts
tend to trigger continously and the error message on the serial console
prevents that the core's detection of spurious interrupts kicks in
(which disables the irq) and just floods the console.

Fixes: c64e7efe46b7 ("spi: stm32: make spurious and overrun interrupts visible")
Signed-off-by: Uwe Kleine-König 
Link: https://msgid.link/r/20240521105241.62400-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown

spi: Assign dummy scatterlist to unidirectional transfers

2024-05-29T15:47:53+00:00

Commit 8cc3bad9d9d6 ("spi: Remove unneded check for orig_nents")
introduced a regression: unmapped data could now be passed to the DMA
APIs, resulting in null pointer dereferences. Commit 9f788ba457b4 ("spi:
Don't mark message DMA mapped when no transfer in it is") and commit
da560097c056 ("spi: Check if transfer is mapped before calling DMA sync
APIs") addressed the problem, but only partially. Unidirectional
transactions will still result in null pointer dereference. To prevent
that from happening, assign a dummy scatterlist when no data is mapped,
so that the DMA API can be called and not result in a null pointer
dereference.

Signed-off-by: Andy Shevchenko 
Reported-by: Neil Armstrong 
Closes: https://lore.kernel.org/r/8ae675b5-fcf9-4c9b-b06a-4462f70e1322@linaro.org
Reported-by: Nícolas F. R. A. Prado 
Closes: https://lore.kernel.org/all/d3679496-2e4e-4a7c-97ed-f193bd53af1d@notapiano
Closes: https://lore.kernel.org/all/4748499f-789c-45a8-b50a-2dd09f4bac8c@notapiano
Fixes: 8cc3bad9d9d6 ("spi: Remove unneded check for orig_nents")
Tested-by: Nícolas F. R. A. Prado 
[nfraprado: wrote the commit message]
Signed-off-by: Nícolas F. R. A. Prado 
Link: https://msgid.link/r/20240529-dma-oops-dummy-v1-1-bb43aacfb11b@collabora.com
Signed-off-by: Mark Brown

spi: cadence: Ensure data lines set to low during dummy-cycle period

2024-05-29T12:43:02+00:00

During dummy-cycles xSPI will switch GPIO into Hi-Z mode. In that dummy
period voltage on data lines will slowly drop, what can cause
unintentional modebyte transmission. Value send to SPI memory chip will
depend on last address, and clock frequency.
To prevent unforeseen consequences of that behaviour, force send
single modebyte(0x00).
Modebyte will be send only if number of dummy-cycles is not equal
to 0. Code must also reduce dummycycle byte count by one - as one byte
is send as modebyte.

Signed-off-by: Witold Sadowski 
Link: https://msgid.link/r/20240529074037.1345882-2-wsadowski@marvell.com
Signed-off-by: Mark Brown

soi: Don't call DMA sync API when not needed

2024-05-23T14:16:57+00:00

Merge series from Andy Shevchenko :

A couple of fixes to avoid calling DMA sync API when it's not needed.
This doesn't stop from discussing if IOMMU code is doing the right thing,
i.e. dereferences SG list when orig_nents == 0, but this is a separate
story.

spi: stm32: Revert change that enabled controller before asserting CS

2024-05-23T11:35:09+00:00

On stm32mp157 enabling the controller before asserting CS makes the
hardware trigger spurious interrupts in a tight loop and the transfers
fail. Revert the commit that swapped the order of enable and CS. This
reintroduces the problem that swapping was supposed to fix, which
however is less grave.

Reported-by: Leonard Göhrs 
Link: https://lore.kernel.org/all/39033ed7-3e57-4339-80b4-fc8919e26aa7@pengutronix.de/
Fixes: 52b62e7a5d4f ("spi: stm32: enable controller before asserting CS")
Signed-off-by: Uwe Kleine-König 
Link: https://msgid.link/r/20240523103326.792907-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown

spi: Check if transfer is mapped before calling DMA sync APIs

2024-05-23T11:32:54+00:00

The resent update to remove the orig_nents checks revealed
that not all DMA sync backends can cope with the unallocated
SG list, while supplying orig_nents == 0 (the commit 861370f49ce4
("iommu/dma: force bouncing if the size is not cacheline-aligned"),
for example, makes that happen for the IOMMU case). It means
we have to check if the buffers are DMA mapped before trying
to sync them. Re-introduce that check in a form of calling
->can_dma() in the same way as it's done in the DMA mapping loop
for the SPI transfers.

Reported-by: Nícolas F. R. A. Prado 
Reported-by: Neil Armstrong 
Closes: https://lore.kernel.org/r/8ae675b5-fcf9-4c9b-b06a-4462f70e1322@linaro.org
Closes: https://lore.kernel.org/all/d3679496-2e4e-4a7c-97ed-f193bd53af1d@notapiano
Fixes: 8cc3bad9d9d6 ("spi: Remove unneded check for orig_nents")
Suggested-by: Nícolas F. R. A. Prado 
Tested-by: Nícolas F. R. A. Prado 
Signed-off-by: Andy Shevchenko 
Link: https://msgid.link/r/20240522171018.3362521-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown

spi: Don't mark message DMA mapped when no transfer in it is

2024-05-23T11:32:52+00:00

There is no need to set the DMA mapped flag of the message if it has
no mapped transfers. Moreover, it may give the code a chance to take
the wrong paths, i.e. to exercise DMA related APIs on unmapped data.
Make __spi_map_msg() to bail earlier on the above mentioned cases.

Fixes: 99adef310f68 ("spi: Provide core support for DMA mapping transfers")
Signed-off-by: Andy Shevchenko 
Link: https://msgid.link/r/20240522171018.3362521-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown

spi: dw: Bail out early on unsupported target mode

2024-05-09T15:48:06+00:00

Currently, the DesignWare SPI controller driver supports only host mode.
However, spi2 on the Kendryte K210 SoC supports only target mode,
triggering an error message on e.g. SiPEED MAiXBiT since commit
98d75b9ef282f6b9 ("spi: dw: Drop default number of CS setting"):

    dw_spi_mmio 50240000.spi: error -22: problem registering spi host
    dw_spi_mmio 50240000.spi: probe with driver dw_spi_mmio failed with error -22

As spi2 rightfully has no "num-cs" property, num_chipselect is now zero,
causing spi_alloc_host() to fail to register the controller.  Before,
the driver silently registered an SPI host controller with 4 chip
selects.

Reject target mode early on and warn the user, getting rid of the
error message.

Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Damien Le Moal 
Link: https://lore.kernel.org/r/7ae28d83bff7351f34782658ae1bb69cc731693e.1715163113.git.geert+renesas@glider.be
Signed-off-by: Mark Brown

spi: microchip-core-qspi: fix setting spi bus clock rate

2024-05-09T04:59:19+00:00

Before ORing the new clock rate with the control register value read
from the hardware, the existing clock rate needs to be masked off as
otherwise the existing value will interfere with the new one.

CC: stable@vger.kernel.org
Fixes: 8596124c4c1b ("spi: microchip-core-qspi: Add support for microchip fpga qspi controllers")
Signed-off-by: Conor Dooley 
Reviewed-by: Tudor Ambarus 
Link: https://lore.kernel.org/r/20240508-fox-unpiloted-b97e1535627b@spud
Signed-off-by: Mark Brown

spi: Remove unneded check for orig_nents

2024-05-08T02:39:46+00:00

Both dma_unmap_sgtable() and sg_free_table() in spi_unmap_buf_attrs()
have checks for orig_nents against 0. No need to duplicate this.
All the same applies to other DMA mapping API calls.

Also note, there is no other user in the kernel that does this kind of
checks.

Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20240507201028.564630-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown