Merge tag 'spi-fix-v7.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "One substantive fix here, fixing corruption of the maximum frequency
  for spi-mem operations which caused users to remember what should have
  been a temporarily modified maximum frequency as the standard going
  forward, potentially causing instability when the modification raised
  rather than lowered the frequency.

  We also have a trivial patch which just documents the correct way to
  describe the Qualcomm IPQ5210 SNAND controller in the DT, there are no
  code changes"

* tag 'spi-fix-v7.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi-mem: avoid mutating op template in spi_mem_supports_op()
  spi: dt-bindings: spi-qpic-snand: Add ipq5210 compatible

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index a09371a075d2..93266848c6df 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -279,13 +279,20 @@ static bool spi_mem_internal_supports_op(struct spi_mem *mem,
  */
 bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
 {
-	/* Make sure the operation frequency is correct before going futher */
-	spi_mem_adjust_op_freq(mem, (struct spi_mem_op *)op);
+	struct spi_mem_op eval_op = *op;
+
+	/*
+	 * Work on a local copy; this is a pure capability check and must
+	 * not modify the caller's op. Stored templates with max_freq == 0
+	 * must remain unset so their frequency is always re-capped to the
+	 * current device maximum at execution time.
+	 */
+	spi_mem_adjust_op_freq(mem, &eval_op);
 
-	if (spi_mem_check_op(op))
+	if (spi_mem_check_op(&eval_op))
 		return false;
 
-	return spi_mem_internal_supports_op(mem, op);
+	return spi_mem_internal_supports_op(mem, &eval_op);
 }
 EXPORT_SYMBOL_GPL(spi_mem_supports_op);