[PATCH 0/2] i2c: imx: two fixes for a DMA write that is not acknowledged

[Mehmet Fide <mehmet.fide@gmail.com>]

From: Mehmet Fide <mehmet.fide@screeningeagle.com>

A write of DMA_THRESHOLD bytes or more to an address that does not
answer leaves the interrupt status behind, so that the next DMA read
returns 0xff for every byte without an error (patch 1), and it blocks
for DMA_TIMEOUT before it fails with -ETIMEDOUT instead of -ENXIO
(patch 2). Patch 2 needs patch 1.

Tested on a Colibri VF50 (i2c0 at 100 kHz, DMA) with v6.12.117, where
the touched code is the same; on this base compile tested only (W=1,
sparse). 200 rounds of failed write, 32 byte read and acknowledged
18 byte write: 200 times ENXIO at once, no wrong read, every write
acknowledged.

Mehmet Fide (2):
  i2c: imx: do not carry the interrupt status over to the next transfer
  i2c: imx: return -ENXIO at once when a DMA write is not acknowledged

 drivers/i2c/busses/i2c-imx.c | 10 ++++++++++
 1 file changed, 10 insertions(+)


base-commit: 25e7ab89f4774b0f842cee0e8a20c11f755924d5
-- 
2.56.0