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From 8a7013f47196abed7e6a40e93d1de1639cd46228 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 10 Jul 2015 17:03:03 +0200
Subject: [PATCH] mmc: sunxi: Don't start commands while the card is busy
Some sdio wifi modules have not been working reliable with the sunxi-mmc
host code. This turns out to be caused by it starting new commands while
the card signals that it is still busy processing a previous command.
This commit fixes this, thereby fixing the wifi reliability issues on
the Cubietruck and other sunxi boards using sdio wifi.
Reported-by: Eugene K <sigintmailru@gmail.com>
Suggested-by: Eugene K <sigintmailru@gmail.com>
Cc: Eugene K <sigintmailru@gmail.com>
Cc: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-Properly accredit Eugene K for coming up with the fix for this
---
drivers/mmc/host/sunxi-mmc.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -289,6 +289,24 @@ static int sunxi_mmc_init_host(struct mm
return 0;
}
+/* Wait for card to report ready before starting a new cmd */
+static int sunxi_mmc_wait_card_ready(struct sunxi_mmc_host *host)
+{
+ unsigned long expire = jiffies + msecs_to_jiffies(500);
+ u32 rval;
+
+ do {
+ rval = mmc_readl(host, REG_STAS);
+ } while (time_before(jiffies, expire) && (rval & SDXC_CARD_DATA_BUSY));
+
+ if (rval & SDXC_CARD_DATA_BUSY) {
+ dev_err(mmc_dev(host->mmc), "Error R1 ready timeout\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
struct mmc_data *data)
{
@@ -383,6 +401,8 @@ static void sunxi_mmc_send_manual_stop(s
u32 arg, cmd_val, ri;
unsigned long expire = jiffies + msecs_to_jiffies(1000);
+ sunxi_mmc_wait_card_ready(host);
+
cmd_val = SDXC_START | SDXC_RESP_EXPIRE |
SDXC_STOP_ABORT_CMD | SDXC_CHECK_RESPONSE_CRC;
@@ -597,6 +617,11 @@ static int sunxi_mmc_oclk_onoff(struct s
{
unsigned long expire = jiffies + msecs_to_jiffies(250);
u32 rval;
+ int ret;
+
+ ret = sunxi_mmc_wait_card_ready(host);
+ if (ret)
+ return ret;
rval = mmc_readl(host, REG_CLKCR);
rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);
@@ -784,6 +809,13 @@ static void sunxi_mmc_request(struct mmc
mmc_request_done(mmc, mrq);
return;
}
+
+ ret = sunxi_mmc_wait_card_ready(host);
+ if (ret) {
+ mrq->cmd->error = ret;
+ mmc_request_done(mmc, mrq);
+ return;
+ }
if (data) {
ret = sunxi_mmc_map_dma(host, data);
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