ARM: mx3: Fix a race condition in mxcmmc (4a31f2ef) · Commits · 戴 / test

From cefcdab08d1c9636c4a7290bc2bbe937d051bce4 Mon Sep 17 00:00:00 2001 From: Volker Ernst <volker.ernst@txtr.com> Date: Mon, 26 Apr 2010 22:51:07 +0200 Subject: [PATCH] ARM: mx3: Fix a race condition in mxcmmc This fixes a race condition regarding interrupt bits in the SDHC controller driver code. In case of PIO-transfer it does not clear SDHC-status bit#11/12 in the INT-handler anymore. INT-handler might be called during an ongoing PIO-data-transfer (with some other INT-flag set) and PIO-transfer depends on these bits being set to detect the end of the data-transfer. This also means that at the end of PIO- transfer that PIO-software has to clear these bits itself. However in case of DMA-transfer these bits have to be cleared in the INT-handler, because they are used to generate INTs then. Works solid, no more problems here, can transfer big files. Signed-off-by:

Volker Ernst <volker.ernst@txtr.com> Acked-by:

Daniel Mack <daniel@caiaq.de> Cc: Andy Green <andy@warmcat.com> Signed-off-by:

Sascha Hauer <s.hauer@pengutronix.de>

drivers/mmc/host/mxcmmc.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -489,6 +489,9 @@ static void mxcmci_datawork(struct work_struct *work)
		struct mxcmci_host *host = container_of(work, struct mxcmci_host,
		datawork);
		int datastat = mxcmci_transfer_data(host);

		writel(STATUS_READ_OP_DONE \| STATUS_WRITE_OP_DONE,
		host->base + MMC_REG_STATUS);
		mxcmci_finish_data(host, datastat);

		if (host->req->stop) {
		@@ -553,7 +556,8 @@ static irqreturn_t mxcmci_irq(int irq, void *devid)
		u32 stat;

		stat = readl(host->base + MMC_REG_STATUS);
		writel(stat & ~STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
		writel(stat & ~(STATUS_SDIO_INT_ACTIVE \| STATUS_DATA_TRANS_DONE \|
		STATUS_WRITE_OP_DONE), host->base + MMC_REG_STATUS);

		dev_dbg(mmc_dev(host->mmc), "%s: 0x%08x\n", __func__, stat);

		@@ -561,6 +565,13 @@ static irqreturn_t mxcmci_irq(int irq, void *devid)
		sdio_irq = (stat & STATUS_SDIO_INT_ACTIVE) && host->use_sdio;
		spin_unlock_irqrestore(&host->lock, flags);

		#ifdef HAS_DMA
		if (mxcmci_use_dma(host) &&
		(stat & (STATUS_READ_OP_DONE \| STATUS_WRITE_OP_DONE)))
		writel(STATUS_READ_OP_DONE \| STATUS_WRITE_OP_DONE,
		host->base + MMC_REG_STATUS);
		#endif

		if (sdio_irq) {
		writel(STATUS_SDIO_INT_ACTIVE, host->base + MMC_REG_STATUS);
		mmc_signal_sdio_irq(host->mmc);

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