Merge tag 'spi-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The big update this time around is some excellent work from David
  Jander who went through the fast path and really eliminated overheads,
  meaning that we are seeing a huge reduction in the time spent between
  transfers for single threaded clients.

  Benchmarking has been coming out at about a halving of overhead which
  is clearly visible in system level usage that stresses SPI like some
  CAN and IIO applications, especially with small transfers. Thanks to
  David for taking the time to drill down into this and push the work
  upstream.

  Otherwise there's been a bunch of new device support and the usual
  updates.

   - Optimisation of the fast path, particularly around the number and
     types of locking operations, from David Jander.

   - Support for Arbel NPCM845, HP GXP, Intel Meteor Lake and Thunder
     Bay, MediaTek MT8188 and MT8365, Microchip FPGAs, nVidia Tegra 241
     and Samsung Exynos Auto v9 and 4210"

* tag 'spi-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (97 commits)
  MAINTAINERS: add spi support to GXP
  spi: dt-bindings: add documentation for hpe,gxp-spifi
  spi: spi-gxp: Add support for HPE GXP SoCs
  spi: a3700: support BE for AC5 SPI driver
  spi/panel: dt-bindings: drop CPHA and CPOL from common properties
  spi: bcm2835: enable shared interrupt support
  spi: dt-bindings: spi-controller: correct example indentation
  spi: dt-bindings: qcom,spi-geni-qcom: allow three interconnects
  spi: npcm-fiu: Add NPCM8XX support
  dt-binding: spi: Add npcm845 compatible to npcm-fiu document
  spi: npcm-fiu: Modify direct read dummy configuration
  spi: atmel: remove #ifdef CONFIG_{PM, SLEEP}
  spi: dt-bindings: Add compatible for MediaTek MT8188
  spi: dt-bindings: mediatek,spi-mtk-nor: Update bindings for nor flash
  spi: dt-bindings: atmel,at91rm9200-spi: convert to json-schema
  spi: tegra20-slink: fix UAF in tegra_slink_remove()
  spi: Fix simplification of devm_spi_register_controller
  spi: microchip-core: switch to use dev_err_probe()
  spi: microchip-core: switch to use devm_spi_alloc_master()
  spi: microchip-core: fix UAF in mchp_corespi_remove()
  ...

1 files changed, 11 insertions, 0 deletions

diff --git a/tools/spi/spidev_test.c b/tools/spi/spidev_test.c
index 83844f8b862a..b0ca44c70e83 100644
--- a/tools/spi/spidev_test.c
+++ b/tools/spi/spidev_test.c
@@ -417,6 +417,7 @@ int main(int argc, char *argv[])
 {
 	int ret = 0;
 	int fd;
+	uint32_t request;
 
 	parse_opts(argc, argv);
 
@@ -430,13 +431,23 @@ int main(int argc, char *argv[])
 	/*
 	 * spi mode
 	 */
+	/* WR is make a request to assign 'mode' */
+	request = mode;
 	ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode);
 	if (ret == -1)
 		pabort("can't set spi mode");
 
+	/* RD is read what mode the device actually is in */
 	ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode);
 	if (ret == -1)
 		pabort("can't get spi mode");
+	/* Drivers can reject some mode bits without returning an error.
+	 * Read the current value to identify what mode it is in, and if it
+	 * differs from the requested mode, warn the user.
+	 */
+	if (request != mode)
+		printf("WARNING device does not support requested mode 0x%x\n",
+			request);
 
 	/*
 	 * bits per word