From f6825748bdbe381cfffe2dc13ca0b73050428fac Mon Sep 17 00:00:00 2001 From: Martin Fuzzey Date: Mon, 15 Apr 2013 17:08:35 +0200 Subject: [PATCH] mmc: sdhci-esdhc-imx: Fix SDIO interrupts Currently SDIO interrupts do not work on i.MX53 and maybe others. This was observed with a Marvell 8787 based SDIO wifi adapter using the mwifiex driver and firmware from the Marvell git repository. The symptom was a timeout after firmware download. Observing the SDIO_DAT1 line showed that an interrupt was requested (level 0) but no interrupt was generated in software, the line stayed low until a timeout ocurred and the card was reset. There is a Freescale errata ENGcm11186 "eSDHC misses SDIO interrupt when CINT is disabled" The workaround suggested by this errata is already implemented and involves clearing and then setting the D3CD bit in the host control register [see esdhc_writel_le()] However, when esdhc_writeb_le() is later used to write to SDHCI_HOST_CONTROL it always resets the D3CD bit. To fix this simply add the D3CD bit to the set of bits not modified by esdhc_writeb_le(). Signed-off-by: Martin Fuzzey Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci-esdhc-imx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 67d6dde2ff19..9b0a0a91ea0a 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -324,8 +324,10 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) /* * Do not touch buswidth bits here. This is done in * esdhc_pltfm_bus_width. + * Do not touch the D3CD bit either which is used for the + * SDIO interrupt errata workaround. */ - mask = 0xffff & ~ESDHC_CTRL_BUSWIDTH_MASK; + mask = 0xffff & ~(ESDHC_CTRL_BUSWIDTH_MASK | ESDHC_CTRL_D3CD); esdhc_clrset_le(host, mask, new_val, reg); return; -- 2.20.1