diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0167-bcm2835-sdhost-Only-claim-one-DMA-channel.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0167-bcm2835-sdhost-Only-claim-one-DMA-channel.patch | 160 |
1 files changed, 0 insertions, 160 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0167-bcm2835-sdhost-Only-claim-one-DMA-channel.patch b/target/linux/brcm2708/patches-4.4/0167-bcm2835-sdhost-Only-claim-one-DMA-channel.patch deleted file mode 100644 index 945c972431..0000000000 --- a/target/linux/brcm2708/patches-4.4/0167-bcm2835-sdhost-Only-claim-one-DMA-channel.patch +++ /dev/null @@ -1,160 +0,0 @@ -From 99864da2b792c10fb95f8c4f56c0a1be376a7f0d Mon Sep 17 00:00:00 2001 -From: Phil Elwell <phil@raspberrypi.org> -Date: Mon, 7 Mar 2016 16:46:39 +0000 -Subject: [PATCH] bcm2835-sdhost: Only claim one DMA channel - -With both MMC controllers enabled there are few DMA channels left. The -bcm2835-sdhost driver only uses DMA in one direction at a time, so it -doesn't need to claim two channels. - -See: https://github.com/raspberrypi/linux/issues/1327 - -Signed-off-by: Phil Elwell <phil@raspberrypi.org> ---- - arch/arm/boot/dts/bcm2708_common.dtsi | 5 +-- - drivers/mmc/host/bcm2835-sdhost.c | 70 ++++++++++++++++++++++++----------- - 2 files changed, 50 insertions(+), 25 deletions(-) - ---- a/arch/arm/boot/dts/bcm2708_common.dtsi -+++ b/arch/arm/boot/dts/bcm2708_common.dtsi -@@ -136,9 +136,8 @@ - reg = <0x7e202000 0x100>; - interrupts = <2 24>; - clocks = <&clk_core>; -- dmas = <&dma 13>, -- <&dma 13>; -- dma-names = "tx", "rx"; -+ dmas = <&dma 13>; -+ dma-names = "rx-tx"; - brcm,overclock-50 = <0>; - brcm,pio-limit = <1>; - status = "disabled"; ---- a/drivers/mmc/host/bcm2835-sdhost.c -+++ b/drivers/mmc/host/bcm2835-sdhost.c -@@ -185,9 +185,10 @@ struct bcm2835_host { - unsigned int debug:1; /* Enable debug output */ - - /*DMA part*/ -- struct dma_chan *dma_chan_rx; /* DMA channel for reads */ -- struct dma_chan *dma_chan_tx; /* DMA channel for writes */ -- struct dma_chan *dma_chan; /* Channel in used */ -+ struct dma_chan *dma_chan_rxtx; /* DMA channel for reads and writes */ -+ struct dma_chan *dma_chan; /* Channel in use */ -+ struct dma_slave_config dma_cfg_rx; -+ struct dma_slave_config dma_cfg_tx; - struct dma_async_tx_descriptor *dma_desc; - u32 dma_dir; - u32 drain_words; -@@ -771,12 +772,11 @@ static void bcm2835_sdhost_prepare_dma(s - log_event("PRD<", (u32)data, 0); - pr_debug("bcm2835_sdhost_prepare_dma()\n"); - -+ dma_chan = host->dma_chan_rxtx; - if (data->flags & MMC_DATA_READ) { -- dma_chan = host->dma_chan_rx; - dir_data = DMA_FROM_DEVICE; - dir_slave = DMA_DEV_TO_MEM; - } else { -- dma_chan = host->dma_chan_tx; - dir_data = DMA_TO_DEVICE; - dir_slave = DMA_MEM_TO_DEV; - } -@@ -813,6 +813,12 @@ static void bcm2835_sdhost_prepare_dma(s - host->drain_words = len/4; - } - -+ /* The parameters have already been validated, so this will not fail */ -+ (void)dmaengine_slave_config(dma_chan, -+ (dir_data == DMA_FROM_DEVICE) ? -+ &host->dma_cfg_rx : -+ &host->dma_cfg_tx); -+ - len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len, - dir_data); - -@@ -1805,28 +1811,46 @@ int bcm2835_sdhost_add_host(struct bcm28 - spin_lock_init(&host->lock); - - if (host->allow_dma) { -- if (IS_ERR_OR_NULL(host->dma_chan_tx) || -- IS_ERR_OR_NULL(host->dma_chan_rx)) { -- pr_err("%s: unable to initialise DMA channels. " -+ if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) { -+ pr_err("%s: unable to initialise DMA channel. " - "Falling back to PIO\n", - mmc_hostname(mmc)); - host->use_dma = false; - } else { -- host->use_dma = true; -- - cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - cfg.slave_id = 13; /* DREQ channel */ - -+ /* Validate the slave configurations */ -+ - cfg.direction = DMA_MEM_TO_DEV; - cfg.src_addr = 0; - cfg.dst_addr = host->bus_addr + SDDATA; -- ret = dmaengine_slave_config(host->dma_chan_tx, &cfg); - -- cfg.direction = DMA_DEV_TO_MEM; -- cfg.src_addr = host->bus_addr + SDDATA; -- cfg.dst_addr = 0; -- ret = dmaengine_slave_config(host->dma_chan_rx, &cfg); -+ ret = dmaengine_slave_config(host->dma_chan_rxtx, &cfg); -+ -+ if (ret == 0) { -+ host->dma_cfg_tx = cfg; -+ -+ cfg.direction = DMA_DEV_TO_MEM; -+ cfg.src_addr = host->bus_addr + SDDATA; -+ cfg.dst_addr = 0; -+ -+ ret = dmaengine_slave_config(host->dma_chan_rxtx, &cfg); -+ } -+ -+ if (ret == 0) { -+ host->dma_cfg_rx = cfg; -+ -+ host->use_dma = true; -+ } else { -+ pr_err("%s: unable to configure DMA channel. " -+ "Falling back to PIO\n", -+ mmc_hostname(mmc)); -+ dma_release_channel(host->dma_chan_rxtx); -+ host->dma_chan_rxtx = NULL; -+ host->use_dma = false; -+ } - } - } else { - host->use_dma = false; -@@ -1948,19 +1972,21 @@ static int bcm2835_sdhost_probe(struct p - - if (host->allow_dma) { - if (node) { -- host->dma_chan_tx = -- dma_request_slave_channel(dev, "tx"); -- host->dma_chan_rx = -- dma_request_slave_channel(dev, "rx"); -+ host->dma_chan_rxtx = -+ dma_request_slave_channel(dev, "rx-tx"); -+ if (!host->dma_chan_rxtx) -+ host->dma_chan_rxtx = -+ dma_request_slave_channel(dev, "tx"); -+ if (!host->dma_chan_rxtx) -+ host->dma_chan_rxtx = -+ dma_request_slave_channel(dev, "rx"); - } else { - dma_cap_mask_t mask; - - dma_cap_zero(mask); - /* we don't care about the channel, any would work */ - dma_cap_set(DMA_SLAVE, mask); -- host->dma_chan_tx = -- dma_request_channel(mask, NULL, NULL); -- host->dma_chan_rx = -+ host->dma_chan_rxtx = - dma_request_channel(mask, NULL, NULL); - } - } |