From: Derong Liu <derong.liu@mediatek.com>
Date: Fri, 27 Aug 2021 07:15:37 +0000 (+0800)
Subject: mmc: mtk-sd: Add wait dma stop done flow
X-Git-Tag: accepted/tizen/unified/20230118.172025~6041
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=20af47eb7fd34f3e7859ebcd82d37d49994b1f73;p=platform%2Fkernel%2Flinux-rpi.git

mmc: mtk-sd: Add wait dma stop done flow

commit 43e5fee317f4b0a48992b8b07935b1a3ac20ce84 upstream.

We found this issue on a 5G platform, during CMDQ error handling, if DMA
status is active when it call msdc_reset_hw(), it means mmc host hw reset
and DMA transfer will be parallel, mmc host may access sram region
unexpectedly. According to the programming guide of mtk-sd host, it needs
to wait for dma stop done after set dma stop.

This change should be applied to all SoCs.

Signed-off-by: Derong Liu <derong.liu@mediatek.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210827071537.1034-1-derong.liu@mediatek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index b06b4dc..9e6dab7 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -8,6 +8,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
+#include <linux/iopoll.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/of_address.h>
@@ -2330,6 +2331,7 @@ static void msdc_cqe_enable(struct mmc_host *mmc)
 static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
 {
 	struct msdc_host *host = mmc_priv(mmc);
+	unsigned int val = 0;
 
 	/* disable cmdq irq */
 	sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INT_CMDQ);
@@ -2339,6 +2341,9 @@ static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
 	if (recovery) {
 		sdr_set_field(host->base + MSDC_DMA_CTRL,
 			      MSDC_DMA_CTRL_STOP, 1);
+		if (WARN_ON(readl_poll_timeout(host->base + MSDC_DMA_CFG, val,
+			!(val & MSDC_DMA_CFG_STS), 1, 3000)))
+			return;
 		msdc_reset_hw(host);
 	}
 }