From e143364b4c1774f68e923a5a0bb0fca28ac25888 Mon Sep 17 00:00:00 2001 From: Noralf Trønnes Date: Fri, 19 Jul 2019 17:59:10 +0200 Subject: drm/tinydrm: Remove tinydrm_spi_max_transfer_size() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit spi-bcm2835 can handle >64kB buffers now so there is no need to check ->max_dma_len. The tinydrm_spi_max_transfer_size() max_len argument is not used by any callers, so not needed. Then we have the spi_max module parameter. It was added because staging/fbtft has support for it and there was a report that someone used it to set a small buffer size to avoid popping on a USB soundcard on a Raspberry Pi. In hindsight it shouldn't have been added, I should have waited for it to become a problem first. I don't know it anyone is actually using it, but since tinydrm_spi_transfer() is being moved to mipi-dbi, I'm taking the opportunity to remove it. I'll add it back to mipi-dbi if someone complains. With that out of the way, spi_max_transfer_size() can be used instead. The chosen 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. Acked-by: Sam Ravnborg Signed-off-by: Noralf Trønnes Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-6-noralf@tronnes.org --- drivers/gpu/drm/tinydrm/mipi-dbi.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'drivers/gpu/drm/tinydrm/mipi-dbi.c') diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c b/drivers/gpu/drm/tinydrm/mipi-dbi.c index 99509d16b037..ae31a5c9aa1b 100644 --- a/drivers/gpu/drm/tinydrm/mipi-dbi.c +++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c @@ -964,15 +964,9 @@ 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 @@ -1001,8 +995,8 @@ 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; } -- cgit