git.openwrt.org Git - openwrt/staging/neocturne.git/blob

   1 From 2862884dd5281299433d641c00d419640bb03d7f Mon Sep 17 00:00:00 2001
   2 From: Jonathan Bell <jonathan@raspberrypi.com>
   3 Date: Tue, 4 Jun 2024 13:45:37 +0100
   4 Subject: [PATCH 1116/1135] mmc: sdhci: extend maximum ADMA transfer length to
   5  4MiB
   6
   7 This gains about 8-12% sequential write speed with the fastest SD/eMMC
   8 cards, and Class A1/A2 card sequential performance is only assured with
   9 a 4MiB write length.
  10
  11 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
  12 ---
  13  drivers/mmc/host/sdhci.c | 15 ++++++++++-----
  14  1 file changed, 10 insertions(+), 5 deletions(-)
  15
  16 --- a/drivers/mmc/host/sdhci.c
  17 +++ b/drivers/mmc/host/sdhci.c
  18 @@ -1081,7 +1081,7 @@ static void sdhci_initialize_data(struct
  19         WARN_ON(host->data);
  20
  21         /* Sanity checks */
  22 -       BUG_ON(data->blksz * data->blocks > 524288);
  23 +       BUG_ON(data->blksz * data->blocks > host->mmc->max_req_size);
  24         BUG_ON(data->blksz > host->mmc->max_blk_size);
  25         BUG_ON(data->blocks > 65535);
  26
  27 @@ -4718,11 +4718,16 @@ int sdhci_setup_host(struct sdhci_host *
  28         spin_lock_init(&host->lock);
  29
  30         /*
  31 -        * Maximum number of sectors in one transfer. Limited by SDMA boundary
  32 -        * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
  33 -        * is less anyway.
  34 +        * Maximum number of sectors in one transfer.
  35 +        * 4MiB is preferred for multi-descriptor DMA as a) card sequential
  36 +        * write speeds are only guaranteed with a 4MiB write length and
  37 +        * b) most tuning modes require a 4MiB limit.
  38 +        * SDMA has a 512KiB boundary size.
  39          */
  40 -       mmc->max_req_size = 524288;
  41 +       if (host->flags & SDHCI_USE_ADMA)
  42 +               mmc->max_req_size = SZ_4M;
  43 +       else
  44 +               mmc->max_req_size = SZ_512K;
  45
  46         /*
  47          * Maximum number of segments. Depends on if the hardware