mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-27 17:18:59 +00:00
5499b24dc0
This backports SATA performance boost from 5.3 kernel: Increasing the SATA/AHCI DMA TX/RX FIFOs (P0DMACR.TXTS and .RXTS, ie. TX_TRANSACTION_SIZE and RX_TRANSACTION_SIZE) from default 0x0 each to 0x3 each, gives a write performance boost of 120 MiB/s to 132 MiB/s from lame 36 MiB/s to 45 MiB/s previously. Read performance is above 200 MiB/s. [tested on SSD using dd bs=4K/8K/12K/16K/20K/24K/32K: peak-perf at 12K] dd bs Before MB/s After MB/s Increase 4k 14.4 16.5 15% 64k 34.5 74.4 116% 1M 40.5 93.2 130% Ref: https://forum.openwrt.org/t/sunxi-sata-write-speed-patch/54555/5 Signed-off-by: Aleksander Jan Bajkowski <A.Bajkowski@stud.elka.pw.edu.pl> [commit subject & description tweaks] Signed-off-by: Petr Štetiar <ynezz@true.cz>
95 lines
3.9 KiB
Diff
95 lines
3.9 KiB
Diff
From 120357ea176e420d313cf8cf2ff35fbe233d3bab Mon Sep 17 00:00:00 2001
|
|
From: Uenal Mutlu <um@mutluit.com>
|
|
Date: Mon, 13 May 2019 16:24:10 +0200
|
|
Subject: [PATCH] drivers: ata: ahci_sunxi: Increased SATA/AHCI DMA TX/RX FIFOs
|
|
|
|
Increasing the SATA/AHCI DMA TX/RX FIFOs (P0DMACR.TXTS and .RXTS, ie.
|
|
TX_TRANSACTION_SIZE and RX_TRANSACTION_SIZE) from default 0x0 each
|
|
to 0x3 each, gives a write performance boost of 120 MiB/s to 132 MiB/s
|
|
from lame 36 MiB/s to 45 MiB/s previously.
|
|
Read performance is above 200 MiB/s.
|
|
[tested on SSD using dd bs=4K/8K/12K/16K/20K/24K/32K: peak-perf at 12K]
|
|
|
|
Tested on the SBCs Banana Pi R1 (aka Lamobo R1) and Banana Pi M1 which
|
|
are based on the Allwinner A20 32bit-SoC (ARMv7-a / arm-linux-gnueabihf).
|
|
These devices are RaspberryPi-like small devices.
|
|
|
|
This problem of slow SATA write-speed with these small devices lasts
|
|
for about 7 years now (beginning with the A10 SoC). Many commentators
|
|
throughout the years wrongly assumed the slow write speed was a
|
|
hardware limitation. This patch finally solves the problem, which
|
|
in fact was just a hard-to-find software problem due to lack of
|
|
SATA/AHCI documentation by the SoC-maker Allwinner Technology.
|
|
|
|
Lists of the affected sunxi and other boards and SoCs with SATA using
|
|
the ahci_sunxi driver:
|
|
$ grep -i -e "^&ahci" arch/arm/boot/dts/sun*dts
|
|
and http://linux-sunxi.org/SATA#Devices_with_SATA_ports
|
|
See also http://linux-sunxi.org/Category:Devices_with_SATA_port
|
|
|
|
Tested-by: Chen-Yu Tsai <wens@csie.org>
|
|
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
|
|
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
|
|
Signed-off-by: Uenal Mutlu <um@mutluit.com>
|
|
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
---
|
|
drivers/ata/ahci_sunxi.c | 47 ++++++++++++++++++++++++++++++++++++++--
|
|
1 file changed, 45 insertions(+), 2 deletions(-)
|
|
|
|
--- a/drivers/ata/ahci_sunxi.c
|
|
+++ b/drivers/ata/ahci_sunxi.c
|
|
@@ -157,8 +157,51 @@ static void ahci_sunxi_start_engine(stru
|
|
void __iomem *port_mmio = ahci_port_base(ap);
|
|
struct ahci_host_priv *hpriv = ap->host->private_data;
|
|
|
|
- /* Setup DMA before DMA start */
|
|
- sunxi_clrsetbits(hpriv->mmio + AHCI_P0DMACR, 0x0000ff00, 0x00004400);
|
|
+ /* Setup DMA before DMA start
|
|
+ *
|
|
+ * NOTE: A similar SoC with SATA/AHCI by Texas Instruments documents
|
|
+ * this Vendor Specific Port (P0DMACR, aka PxDMACR) in its
|
|
+ * User's Guide document (TMS320C674x/OMAP-L1x Processor
|
|
+ * Serial ATA (SATA) Controller, Literature Number: SPRUGJ8C,
|
|
+ * March 2011, Chapter 4.33 Port DMA Control Register (P0DMACR),
|
|
+ * p.68, https://www.ti.com/lit/ug/sprugj8c/sprugj8c.pdf)
|
|
+ * as equivalent to the following struct:
|
|
+ *
|
|
+ * struct AHCI_P0DMACR_t
|
|
+ * {
|
|
+ * unsigned TXTS : 4;
|
|
+ * unsigned RXTS : 4;
|
|
+ * unsigned TXABL : 4;
|
|
+ * unsigned RXABL : 4;
|
|
+ * unsigned Reserved : 16;
|
|
+ * };
|
|
+ *
|
|
+ * TXTS: Transmit Transaction Size (TX_TRANSACTION_SIZE).
|
|
+ * This field defines the DMA transaction size in DWORDs for
|
|
+ * transmit (system bus read, device write) operation. [...]
|
|
+ *
|
|
+ * RXTS: Receive Transaction Size (RX_TRANSACTION_SIZE).
|
|
+ * This field defines the Port DMA transaction size in DWORDs
|
|
+ * for receive (system bus write, device read) operation. [...]
|
|
+ *
|
|
+ * TXABL: Transmit Burst Limit.
|
|
+ * This field allows software to limit the VBUSP master read
|
|
+ * burst size. [...]
|
|
+ *
|
|
+ * RXABL: Receive Burst Limit.
|
|
+ * Allows software to limit the VBUSP master write burst
|
|
+ * size. [...]
|
|
+ *
|
|
+ * Reserved: Reserved.
|
|
+ *
|
|
+ *
|
|
+ * NOTE: According to the above document, the following alternative
|
|
+ * to the code below could perhaps be a better option
|
|
+ * (or preparation) for possible further improvements later:
|
|
+ * sunxi_clrsetbits(hpriv->mmio + AHCI_P0DMACR, 0x0000ffff,
|
|
+ * 0x00000033);
|
|
+ */
|
|
+ sunxi_clrsetbits(hpriv->mmio + AHCI_P0DMACR, 0x0000ffff, 0x00004433);
|
|
|
|
/* Start DMA */
|
|
sunxi_setbits(port_mmio + PORT_CMD, PORT_CMD_START);
|