Merge tag 'mmc-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc

Pull MMC updates from Ulf Hansson:
 "MMC core:
   - Add a power-off-delay-us DT property to support HW specific delays
   - Add mmc_send_tuning_timeout() to allow hosts to specify a timeout
   - Enable hosts to control the re-programming of the crypto keys

  MMC host:
   - dw_mmc: Add a common watchdog and convert the various timeouts to use it
   - dw_mmc: Expose the watchdog state in debugfs
   - dw_mmc-rockchip: Use a tighter per command tuning timeout
   - greybus-sdio: Convert to devm_mmc_alloc_host()
   - meson-gx: Enable the bus pipeline clock on T7
   - rtsx_usb_sdmmc: Start card power-up at 3.3V
   - sdhci-cadence: Add Altera Agilex5 SD6HC support
   - sdhci-cadence: Add Cadence SD6HC support
   - sdhci-msm: Add support for the MSM8952 and Maili variants
   - sdhci-msm: Use pm ops to better manage restoring of crypto keys
   - sdhci-of-dwcmshc: Disable CQE error halt request for Rockchip
   - sdhci-pxav3: Disable clock inversion for SD HS cards
   - sunplus: Fixup initialization for DDR modes
   - sunxi: Add support for Allwinner B288
   - vub300: Remove the driver for the obsolete HW"

* tag 'mmc-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (43 commits)
  dt-bindings: mmc: sun4i-a10-mmc: add Allwinner B288
  mmc: dw_mmc-rockchip: use a tighter per-command tuning timeout
  mmc: core: add mmc_send_tuning_timeout()
  mmc: sdhci-of-dwcmshc: Disable CQE error halt request for Rockchip
  dt-bindings: mmc: sdhci-msm: Add MSM8952 compatible
  mmc: use assign_bit() where applicable
  mmc: sdhci-pci: Replace deprecated PCI functions
  mmc: sunplus: initialise rd_crc_dly=1 for DDR modes
  mmc: core: fix stale mmc_start_req() references in comments
  docs: mmc: fix stale async request documentation
  docs: mmc: document eMMC health status support in mmc-tools
  mmc: cavium-thunderx: Drop redundant calls to get|put_device()
  mmc: core: Turn mmc_alloc|free_host() into static functions
  staging: greybus: sdio: Convert to devm_mmc_alloc_host()
  mmc: vub300: Remove the driver for the obsolete HW
  mmc: dw_mmc: remove unused slot member
  mmc: sdhci-pxav3: avoid of_node
  CREDITS: Add Pierre Ossman
  mmc: fix typos in comments
  mmc: meson-gx: enable the bus pipeline clock on T7
  ...

2 files changed, 14 insertions, 51 deletions

diff --git a/Documentation/driver-api/mmc/mmc-async-req.rst b/Documentation/driver-api/mmc/mmc-async-req.rst
index 0f7197c9c3b5..d9d4ac74b846 100644
--- a/Documentation/driver-api/mmc/mmc-async-req.rst
+++ b/Documentation/driver-api/mmc/mmc-async-req.rst
@@ -23,7 +23,7 @@ MMC request.
 MMC block driver
 ================
 
-The mmc_blk_issue_rw_rq() in the MMC block driver is made non-blocking.
+The mmc_blk_mq_issue_rw_rq() in the MMC block driver is made non-blocking.
 
 The increase in throughput is proportional to the time it takes to
 prepare (major part of preparations are dma_map_sg() and dma_unmap_sg())
@@ -34,21 +34,20 @@ platform. In power save mode, when clocks run on a lower frequency, the DMA
 preparation may cost even more. As long as these slower preparations are run
 in parallel with the transfer performance won't be affected.
 
-Details on measurements from IOZone and mmc_test
-================================================
+MMC core API
+============
 
-https://wiki.linaro.org/WorkingGroups/Kernel/Specs/StoragePerfMMC-async-req
+The preparation of a request is separated from starting the transfer, so
+that a host can prepare a request while another one is still in progress:
 
-MMC core API extension
-======================
-
-There is one new public function mmc_start_req().
-
-It starts a new MMC command request for a host. The function isn't
-truly non-blocking. If there is an ongoing async request it waits
-for completion of that request and starts the new one and returns. It
-doesn't wait for the new request to complete. If there is no ongoing
-request it starts the new request and returns immediately.
+ * mmc_pre_req() prepares a request before it is started. It may be called
+   while another request is running on the host.
+ * mmc_start_request() starts a prepared request without waiting for it to
+   complete. mmc_wait_for_req() starts a request and waits for it to
+   complete as well.
+ * mmc_post_req() releases the resources allocated by mmc_pre_req() after
+   the request has completed. It may likewise run while another request is
+   active.
 
 MMC host extensions
 ===================
@@ -59,40 +58,3 @@ to before and after the actual mmc_host_ops.request() function is called.
 
 In the DMA case pre_req() may do dma_map_sg() and prepare the DMA
 descriptor, and post_req() runs the dma_unmap_sg().
-
-Optimize for the first request
-==============================
-
-The first request in a series of requests can't be prepared in parallel
-with the previous transfer, since there is no previous request.
-
-The argument is_first_req in pre_req() indicates that there is no previous
-request. The host driver may optimize for this scenario to minimize
-the performance loss. A way to optimize for this is to split the current
-request in two chunks, prepare the first chunk and start the request,
-and finally prepare the second chunk and start the transfer.
-
-Pseudocode to handle is_first_req scenario with minimal prepare overhead::
-
-  if (is_first_req && req->size > threshold)
-     /* start MMC transfer for the complete transfer size */
-     mmc_start_command(MMC_CMD_TRANSFER_FULL_SIZE);
-
-     /*
-      * Begin to prepare DMA while cmd is being processed by MMC.
-      * The first chunk of the request should take the same time
-      * to prepare as the "MMC process command time".
-      * If prepare time exceeds MMC cmd time
-      * the transfer is delayed, guesstimate max 4k as first chunk size.
-      */
-      prepare_1st_chunk_for_dma(req);
-      /* flush pending desc to the DMAC (dmaengine.h) */
-      dma_issue_pending(req->dma_desc);
-
-      prepare_2nd_chunk_for_dma(req);
-      /*
-       * The second issue_pending should be called before MMC runs out
-       * of the first chunk. If the MMC runs out of the first data chunk
-       * before this call, the transfer is delayed.
-       */
-      dma_issue_pending(req->dma_desc);
diff --git a/Documentation/driver-api/mmc/mmc-tools.rst b/Documentation/driver-api/mmc/mmc-tools.rst
index eee1c2ccfa8f..728d3aa67eda 100644
--- a/Documentation/driver-api/mmc/mmc-tools.rst
+++ b/Documentation/driver-api/mmc/mmc-tools.rst
@@ -32,6 +32,7 @@ The mmc-utils tools can do the following:
  - Write to rpmb device from data file.
  - Enable the eMMC cache feature.
  - Disable the eMMC cache feature.
+ - Print the eMMC health status.
  - Print and parse CID data.
  - Print and parse CSD data.
  - Print and parse SCR data.