From: Meghana Madhyastha <meghana.madhyas...@gmail.com>
Remove chunk splitting in tinydrm_spi_transfer in tinydrm-helpers as the
spi core will split a buffer into max_dma_len chunks for the spi
controller driver to handle, automatic byte swapping in
tinydrm_spi_transfer as it doesn't have users.
Remove the spi_max module argument that now has lost its cause.
The 16kB buffer size for Type C Option 1 (9-bit) interface is somewhat
arbitrary, but a bigger buffer will have a miniscule impact on transfer
speed, so it's probably fine.
Signed-off-by: Meghana Madhyastha <meghana.madhyas...@gmail.com>
Signed-off-by: Noralf Trønnes <nor...@tronnes.org>
---
.../gpu/drm/tinydrm/core/tinydrm-helpers.c | 83 ++-----------------
drivers/gpu/drm/tinydrm/mipi-dbi.c | 10 +--
2 files changed, 7 insertions(+), 86 deletions(-)
diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
index 6d540d93758f..a32dc859a9c1 100644
--- a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
@@ -22,41 +22,8 @@
#include <drm/drm_rect.h>
#include <drm/tinydrm/tinydrm-helpers.h>
-static unsigned int spi_max;
-module_param(spi_max, uint, 0400);
-MODULE_PARM_DESC(spi_max, "Set a lower SPI max transfer size");
-
#if IS_ENABLED(CONFIG_SPI)
-/**
- * tinydrm_spi_max_transfer_size - Determine max SPI transfer size
- * @spi: SPI device
- * @max_len: Maximum buffer size needed (optional)
- *
- * This function returns the maximum size to use for SPI transfers. It checks
- * the SPI master, the optional @max_len and the module parameter spi_max and
- * returns the smallest.
- *
- * Returns:
- * Maximum size for SPI transfers
- */
-size_t tinydrm_spi_max_transfer_size(struct spi_device *spi, size_t max_len)
-{
- size_t ret;
-
- ret = min(spi_max_transfer_size(spi), spi->master->max_dma_len);
- if (max_len)
- ret = min(ret, max_len);
- if (spi_max)
- ret = min_t(size_t, ret, spi_max);
- ret &= ~0x3;
- if (ret < 4)
- ret = 4;
-
- return ret;
-}
-EXPORT_SYMBOL(tinydrm_spi_max_transfer_size);
-
/**
* tinydrm_spi_bpw_supported - Check if bits per word is supported
* @spi: SPI device
@@ -147,62 +114,22 @@ int tinydrm_spi_transfer(struct spi_device *spi, u32
speed_hz,
struct spi_transfer tr = {
.bits_per_word = bpw,
.speed_hz = speed_hz,
+ .tx_buf = buf,
+ .len = len
};
struct spi_message m;
- u16 *swap_buf = NULL;
- size_t max_chunk;
- size_t chunk;
- int ret = 0;
-
- if (WARN_ON_ONCE(bpw != 8 && bpw != 16))
- return -EINVAL;
-
- max_chunk = tinydrm_spi_max_transfer_size(spi, 0);
if (drm_debug & DRM_UT_DRIVER)
- pr_debug("[drm:%s] bpw=%u, max_chunk=%zu, transfers:\n",
- __func__, bpw, max_chunk);
-
- if (bpw == 16 && !tinydrm_spi_bpw_supported(spi, 16)) {
- tr.bits_per_word = 8;
- if (tinydrm_machine_little_endian()) {
- swap_buf = kmalloc(min(len, max_chunk), GFP_KERNEL);
- if (!swap_buf)
- return -ENOMEM;
- }
- }
+ pr_debug("[drm:%s] bpw=%u, transfers:\n", __func__, bpw);
spi_message_init(&m);
if (header)
spi_message_add_tail(header, &m);
spi_message_add_tail(&tr, &m);
- while (len) {
- chunk = min(len, max_chunk);
+ tinydrm_dbg_spi_message(spi, &m);
- tr.tx_buf = buf;
- tr.len = chunk;
-
- if (swap_buf) {
- const u16 *buf16 = buf;
- unsigned int i;
-
- for (i = 0; i < chunk / 2; i++)
- swap_buf[i] = swab16(buf16[i]);
-
- tr.tx_buf = swap_buf;
- }
-
- buf += chunk;
- len -= chunk;
-
- tinydrm_dbg_spi_message(spi, &m);
- ret = spi_sync(spi, &m);
- if (ret)
- return ret;
- }
-
- return 0;
+ return spi_sync(spi, &m);
}
EXPORT_SYMBOL(tinydrm_spi_transfer);
diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c
b/drivers/gpu/drm/tinydrm/mipi-dbi.c
index 85761b4abb83..0bcf6c764893 100644
--- a/drivers/gpu/drm/tinydrm/mipi-dbi.c
+++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c
@@ -975,15 +975,9 @@ static int mipi_dbi_typec3_command(struct mipi_dbi *mipi,
u8 *cmd,
int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *mipi,
struct gpio_desc *dc)
{
- size_t tx_size = tinydrm_spi_max_transfer_size(spi, 0);
struct device *dev = &spi->dev;
int ret;
- if (tx_size < 16) {
- DRM_ERROR("SPI transmit buffer too small: %zu\n", tx_size);
- return -EINVAL;
- }
-
/*
* Even though it's not the SPI device that does DMA (the master does),
* the dma mask is necessary for the dma_alloc_wc() in
@@ -1013,8 +1007,8 @@ int mipi_dbi_spi_init(struct spi_device *spi, struct
mipi_dbi *mipi,
mipi->swap_bytes = true;
} else {
mipi->command = mipi_dbi_typec1_command;
- mipi->tx_buf9_len = tx_size;
- mipi->tx_buf9 = devm_kmalloc(dev, tx_size, GFP_KERNEL);
+ mipi->tx_buf9_len = SZ_16K;
+ mipi->tx_buf9 = devm_kmalloc(dev, mipi->tx_buf9_len,
GFP_KERNEL);
if (!mipi->tx_buf9)
return -ENOMEM;
}
--
2.20.1
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
