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Message-ID: <7982aae5-ac38-03df-aa0a-165c3c3f7764@intel.com>
Date: Mon, 29 May 2023 17:10:45 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: Stephan Gerhold <stephan@...hold.net>,
Ulf Hansson <ulf.hansson@...aro.org>
Cc: Bjorn Andersson <andersson@...nel.org>,
Andy Gross <agross@...nel.org>,
Konrad Dybcio <konrad.dybcio@...aro.org>,
linux-arm-msm@...r.kernel.org, linux-mmc@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mmc: sdhci-msm: Disable broken 64-bit DMA on MSM8916
On 18/05/23 12:39, Stephan Gerhold wrote:
> While SDHCI claims to support 64-bit DMA on MSM8916 it does not seem to
> be properly functional. It is not immediately obvious because SDHCI is
> usually used with IOMMU bypassed on this SoC, and all physical memory
> has 32-bit addresses. But when trying to enable the IOMMU it quickly
> fails with an error such as the following:
>
> arm-smmu 1e00000.iommu: Unhandled context fault:
> fsr=0x402, iova=0xfffff200, fsynr=0xe0000, cbfrsynra=0x140, cb=3
> mmc1: ADMA error: 0x02000000
> mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
> mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00002e02
> mmc1: sdhci: Blk size: 0x00000008 | Blk cnt: 0x00000000
> mmc1: sdhci: Argument: 0x00000000 | Trn mode: 0x00000013
> mmc1: sdhci: Present: 0x03f80206 | Host ctl: 0x00000019
> mmc1: sdhci: Power: 0x0000000f | Blk gap: 0x00000000
> mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x00000007
> mmc1: sdhci: Timeout: 0x0000000a | Int stat: 0x00000001
> mmc1: sdhci: Int enab: 0x03ff900b | Sig enab: 0x03ff100b
> mmc1: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
> mmc1: sdhci: Caps: 0x322dc8b2 | Caps_1: 0x00008007
> mmc1: sdhci: Cmd: 0x0000333a | Max curr: 0x00000000
> mmc1: sdhci: Resp[0]: 0x00000920 | Resp[1]: 0x5b590000
> mmc1: sdhci: Resp[2]: 0xe6487f80 | Resp[3]: 0x0a404094
> mmc1: sdhci: Host ctl2: 0x00000008
> mmc1: sdhci: ADMA Err: 0x00000001 | ADMA Ptr: 0x0000000ffffff224
> mmc1: sdhci_msm: ----------- VENDOR REGISTER DUMP -----------
> mmc1: sdhci_msm: DLL sts: 0x00000000 | DLL cfg: 0x60006400 | DLL cfg2: 0x00000000
> mmc1: sdhci_msm: DLL cfg3: 0x00000000 | DLL usr ctl: 0x00000000 | DDR cfg: 0x00000000
> mmc1: sdhci_msm: Vndr func: 0x00018a9c | Vndr func2 : 0xf88018a8 Vndr func3: 0x00000000
> mmc1: sdhci: ============================================
> mmc1: sdhci: fffffffff200: DMA 0x0000ffffffffe100, LEN 0x0008, Attr=0x21
> mmc1: sdhci: fffffffff20c: DMA 0x0000000000000000, LEN 0x0000, Attr=0x03
>
> Looking closely it's obvious that only the 32-bit part of the address
> (0xfffff200) arrives at the SMMU, the higher 16-bit (0xffff...) get
> lost somewhere. This might not be a limitation of the SDHCI itself but
> perhaps the bus/interconnect it is connected to, or even the connection
> to the SMMU.
>
> Work around this by setting SDHCI_QUIRK2_BROKEN_64_BIT_DMA to avoid
> using 64-bit addresses.
>
> Signed-off-by: Stephan Gerhold <stephan@...hold.net>
Acked-by: Adrian Hunter <adrian.hunter@...el.com>
> ---
> drivers/mmc/host/sdhci-msm.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 8ac81d57a3df..1877d583fe8c 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2479,6 +2479,9 @@ static inline void sdhci_msm_get_of_property(struct platform_device *pdev,
> msm_host->ddr_config = DDR_CONFIG_POR_VAL;
>
> of_property_read_u32(node, "qcom,dll-config", &msm_host->dll_config);
> +
> + if (of_device_is_compatible(node, "qcom,msm8916-sdhci"))
> + host->quirks2 |= SDHCI_QUIRK2_BROKEN_64_BIT_DMA;
> }
>
> static int sdhci_msm_gcc_reset(struct device *dev, struct sdhci_host *host)
>
> ---
> base-commit: d4ebc9419afbac330e9ec0d2936108742aa4d97a
> change-id: 20230518-msm8916-64bit-f5bcf6af7679
>
> Best regards,
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