From: Meghana Madhyastha <meghana.madhyastha@xxxxxxxxx> Remove chunk splitting in tinydrm_spi_transfer in tinydrm-helpers as spi-bcm2835 now can handle large buffers using DMA, 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.madhyastha@xxxxxxxxx> Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> --- .../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