From: Sean Anderson <seanga2@gmail.com>
To: u-boot@lists.denx.de
Subject: [PATCH v5 22/33] spi: dw: Speed up transfer loops
Date: Fri, 28 Feb 2020 16:05:40 -0500 [thread overview]
Message-ID: <20200228210552.615672-23-seanga2@gmail.com> (raw)
In-Reply-To: <20200228210552.615672-1-seanga2@gmail.com>
The transfer loops are very tight on some platforms (especially on higher
speeds). If we don't read/write fast enough we can run into over-/under-
flow problems. This patch removes several divisions and log statements,
and simplifies the read logic.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
---
Changes in v5:
- New
drivers/spi/designware_spi.c | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)
diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c
index 38c24fe550..613eb0d0e6 100644
--- a/drivers/spi/designware_spi.c
+++ b/drivers/spi/designware_spi.c
@@ -304,7 +304,7 @@ static inline u32 tx_max(struct dw_spi_priv *priv)
{
u32 tx_left, tx_room, rxtx_gap;
- tx_left = (priv->tx_end - priv->tx) / (priv->bits_per_word >> 3);
+ tx_left = priv->tx_end - priv->tx;
tx_room = priv->fifo_len - dw_read(priv, DW_SPI_TXFLR);
/*
@@ -315,8 +315,7 @@ static inline u32 tx_max(struct dw_spi_priv *priv)
* shift registers. So a control from sw point of
* view is taken.
*/
- rxtx_gap = ((priv->rx_end - priv->rx) - (priv->tx_end - priv->tx)) /
- (priv->bits_per_word >> 3);
+ rxtx_gap = ((priv->rx_end - priv->rx) - (priv->tx_end - priv->tx));
return min3(tx_left, tx_room, (u32)(priv->fifo_len - rxtx_gap));
}
@@ -324,7 +323,7 @@ static inline u32 tx_max(struct dw_spi_priv *priv)
/* Return the max entries we should read out of rx fifo */
static inline u32 rx_max(struct dw_spi_priv *priv)
{
- u32 rx_left = (priv->rx_end - priv->rx) / (priv->bits_per_word >> 3);
+ u32 rx_left = priv->rx_end - priv->rx;
return min_t(u32, rx_left, dw_read(priv, DW_SPI_RXFLR));
}
@@ -336,15 +335,10 @@ static void dw_writer(struct dw_spi_priv *priv)
while (max--) {
/* Set the tx word if the transfer's original "tx" is not null */
- if (priv->tx_end - priv->len) {
- if (priv->bits_per_word == 8)
- txw = *(u8 *)(priv->tx);
- else
- txw = *(u16 *)(priv->tx);
- }
+ if (priv->tx_end - priv->len)
+ txw = *(u8 *)(priv->tx);
dw_write(priv, DW_SPI_DR, txw);
- debug("%s: tx=0x%02x\n", __func__, txw);
- priv->tx += priv->bits_per_word >> 3;
+ priv->tx++;
}
}
@@ -355,16 +349,11 @@ static void dw_reader(struct dw_spi_priv *priv)
while (max--) {
rxw = dw_read(priv, DW_SPI_DR);
- debug("%s: rx=0x%02x\n", __func__, rxw);
/* Care about rx if the transfer's original "rx" is not null */
- if (priv->rx_end - priv->len) {
- if (priv->bits_per_word == 8)
- *(u8 *)(priv->rx) = rxw;
- else
- *(u16 *)(priv->rx) = rxw;
- }
- priv->rx += priv->bits_per_word >> 3;
+ if (priv->rx_end - priv->len)
+ *(u8 *)(priv->rx) = rxw;
+ priv->rx++;
}
}
--
2.25.0
next prev parent reply other threads:[~2020-02-28 21:05 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-28 21:05 [PATCH v5 00/33] riscv: Add Sipeed Maix support Sean Anderson
2020-02-28 21:05 ` [PATCH v5 01/33] clk: Always use the supplied struct clk Sean Anderson
2020-02-28 21:05 ` [PATCH v5 02/33] clk: Check that ops of composite clock components exist before calling Sean Anderson
2020-02-28 21:05 ` [PATCH v5 03/33] clk: Unconditionally recursively en-/dis-able clocks Sean Anderson
2020-03-04 6:50 ` Rick Chen
2020-02-28 21:05 ` [PATCH v5 04/33] clk: Add functions to register CCF clock structs Sean Anderson
2020-02-28 21:05 ` [PATCH v5 05/33] clk: Add K210 pll support Sean Anderson
2020-02-28 21:05 ` [PATCH v5 06/33] clk: Add a bypass clock for K210 Sean Anderson
2020-02-28 21:05 ` [PATCH v5 07/33] clk: Add K210 clock support Sean Anderson
2020-03-04 6:58 ` Rick Chen
2020-03-04 14:54 ` Sean Anderson
2020-02-28 21:05 ` [PATCH v5 08/33] doc: Fix typo in FIT documentation Sean Anderson
2020-03-02 2:21 ` Bin Meng
2020-02-28 21:05 ` [PATCH v5 09/33] dm: Add support for simple-pm-bus Sean Anderson
2020-02-28 21:05 ` [PATCH v5 10/33] dm: Fix error handling for dev_read_addr_ptr Sean Anderson
2020-03-02 2:22 ` Bin Meng
2020-03-02 19:46 ` Simon Glass
2020-02-28 21:05 ` [PATCH v5 11/33] reset: Add generic reset driver Sean Anderson
2020-02-28 21:05 ` [PATCH v5 12/33] lib: Always set errno in hcreate_r Sean Anderson
2020-03-02 2:24 ` Bin Meng
2020-02-28 21:05 ` [PATCH v5 13/33] pinctrl: Add support for Kendryte K210 FPIOA Sean Anderson
2020-03-04 6:47 ` Rick Chen
2020-03-04 15:00 ` Sean Anderson
2020-02-28 21:05 ` [PATCH v5 14/33] gpio: sifive: Use generic reg read function Sean Anderson
2020-03-02 2:24 ` Bin Meng
2020-02-28 21:05 ` [PATCH v5 15/33] gpio: dw: Fix warnings about casting int to pointer Sean Anderson
2020-03-02 2:27 ` Bin Meng
2020-03-02 3:50 ` Sean Anderson
2020-02-28 21:05 ` [PATCH v5 16/33] gpio: dw: Add a trailing underscore to generated name Sean Anderson
2020-02-28 21:05 ` [PATCH v5 17/33] gpio: dw: Return output value when direction is out Sean Anderson
2020-02-28 21:05 ` [PATCH v5 18/33] led: gpio: Default to using node name if label is absent Sean Anderson
2020-02-28 21:05 ` [PATCH v5 19/33] spi: dw: Add device tree properties for fields in CTRL1 Sean Anderson
2020-03-04 6:15 ` Rick Chen
2020-03-04 15:01 ` Sean Anderson
2020-02-28 21:05 ` [PATCH v5 20/33] spi: dw: Rename "cs-gpio" to "cs-gpios" Sean Anderson
2020-02-28 21:05 ` [PATCH v5 21/33] spi: dw: Use generic function to read reg address Sean Anderson
2020-02-28 21:05 ` Sean Anderson [this message]
2020-02-28 21:05 ` [PATCH v5 23/33] spi: dw: Properly set rx_end when not recieving Sean Anderson
2020-02-29 17:47 ` Sean Anderson
2020-02-28 21:05 ` [PATCH v5 24/33] spi: dw: Add mem_ops Sean Anderson
2020-02-28 21:05 ` [PATCH v5 25/33] wdt: Move asm/utils.h to log2.h Sean Anderson
2020-02-28 21:46 ` Marek Vasut
2020-02-28 22:43 ` Sean Anderson
2020-02-28 23:27 ` Marek Vasut
2020-03-03 6:58 ` Rick Chen
2020-03-03 14:11 ` Sean Anderson
2020-02-28 21:05 ` [PATCH v5 26/33] riscv: Add headers for asm/global_data.h Sean Anderson
2020-02-28 21:05 ` [PATCH v5 27/33] riscv: Fix race conditions when initializing IPI Sean Anderson
2020-03-02 9:08 ` Rick Chen
2020-03-02 15:43 ` Sean Anderson
2020-03-02 23:15 ` Lukas Auer
2020-03-03 8:27 ` Rick Chen
2020-03-05 2:18 ` Rick Chen
2020-03-02 23:17 ` Lukas Auer
2020-03-02 23:43 ` Sean Anderson
2020-03-03 21:53 ` Lukas Auer
2020-03-03 21:57 ` Sean Anderson
2020-03-04 15:25 ` Lukas Auer
2020-02-28 21:05 ` [PATCH v5 28/33] riscv: Add option to support RISC-V privileged spec 1.9 Sean Anderson
2020-03-04 6:20 ` Rick Chen
2020-02-28 21:05 ` [PATCH v5 29/33] riscv: Allow use of reset drivers Sean Anderson
2020-02-28 21:05 ` [PATCH v5 30/33] riscv: Try to get cpu frequency from a "clocks" node if it exists Sean Anderson
2020-02-28 21:05 ` [PATCH v5 31/33] riscv: Enable cpu clock if it is present Sean Anderson
2020-02-28 21:05 ` [PATCH v5 32/33] riscv: Add device tree for K210 and Sipeed Maix BitM Sean Anderson
2020-02-28 21:05 ` [PATCH v5 33/33] riscv: Add Sipeed Maix support Sean Anderson
2020-03-04 6:04 ` Rick Chen
2020-03-04 7:47 ` Rick Chen
2020-03-04 15:11 ` Sean Anderson
2020-03-05 3:40 ` Bin Meng
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