From fe48f0941e309751a210cacf6435632d86009ab4 Mon Sep 17 00:00:00 2001 From: Furquan Shaikh Date: Mon, 13 Jul 2015 09:48:52 -0700 Subject: [PATCH] t210: Correct dma_busy function In case of continuous mode, use STA_ACTIVITY bit to determine if DMA operation is complete. However, in case of ONCE mode, use STA_BSY bit to determine if DMA operation on the channel is complete. BUG=chrome-os-partner:41877 BRANCH=None TEST=Compiles successfully and reboot test runs fine for 10K+ iterations Change-Id: If98f195481b18c402bd9cac353080c317e0e1168 Signed-off-by: Patrick Georgi Original-Commit-Id: 927026db6fd910dac32dc218f28efcbc7b788b4e Original-Change-Id: Ib66bedfb413f948728a4f9cffce9d9c3feb0bfda Original-Signed-off-by: Furquan Shaikh Original-Reviewed-on: https://chromium-review.googlesource.com/285140 Original-Tested-by: Furquan Shaikh Original-Reviewed-by: Aaron Durbin Original-Commit-Queue: Furquan Shaikh Original-Trybot-Ready: Furquan Shaikh Reviewed-on: http://review.coreboot.org/10946 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/soc/nvidia/tegra210/dma.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/src/soc/nvidia/tegra210/dma.c b/src/soc/nvidia/tegra210/dma.c index 9f04e9777f..fb986923f9 100644 --- a/src/soc/nvidia/tegra210/dma.c +++ b/src/soc/nvidia/tegra210/dma.c @@ -69,9 +69,21 @@ int dma_busy(struct apb_dma_channel * const channel) * In continuous mode, the BSY_n bit in APB_DMA_STATUS and * BSY in APBDMACHAN_CHANNEL_n_STA_0 will remain set as '1' so long * as the channel is enabled. So for this function we'll use the - * DMA_ACTIVITY bit. + * DMA_ACTIVITY bit in case of continuous mode. + * + * However, for ONCE mode, the BSY_n bit in APB_DMA_STATUS will be used + * to determine end of dma operation. */ - return read32(&channel->regs->sta) & APB_STA_DMA_ACTIVITY ? 1 : 0; + uint32_t bit; + + if (read32(&channel->regs->csr) & APB_CSR_ONCE) + /* Once mode */ + bit = APB_STA_BSY; + else + /* Continuous mode */ + bit = APB_STA_DMA_ACTIVITY; + + return read32(&channel->regs->sta) & bit ? 1 : 0; } /* claim a DMA channel */ struct apb_dma_channel * const dma_claim(void)