Re: [PATCH v8 4/4] riscv: dts: thead: Enable LicheePi 4A eMMC and microSD

Drew Fustini
2024-03-02T16:25:58Z

On Sat, Mar 02, 2024 at 10:13:55PM +0800, Xi Ruoyao wrote:
> On Wed, 2023-12-06 at 00:09 -0800, Drew Fustini wrote:
> > Add emmc node properties for the eMMC device and add sdio0 node
> > properties for the microSD slot. Set the frequency for the sdhci
> > reference clock.
>
> Hi Drew,
>
> I've been using the emmc on LicheePi 4A for a while without any problem,
> but when I try the microSD slot I get:
>
> [ 0.531804] mmc1: SDHCI controller on ffe7090000.mmc [ffe7090000.mmc] using ADMA 64-bit
> [ 0.842674] mmc1: Tuning failed, falling back to fixed sampling clock
> [ 0.855139] mmc1: tuning execution failed: -5
> [ 0.859609] mmc1: error -5 whilst initialising SD card
> [ 11.359879] mmc1: Timeout waiting for hardware cmd interrupt.
> [ 11.365661] mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
> [ 11.372105] mmc1: sdhci: Sys addr: 0x00000001 | Version: 0x00000005
> [ 11.378547] mmc1: sdhci: Blk size: 0x00007040 | Blk cnt: 0x00000000
> [ 11.384989] mmc1: sdhci: Argument: 0x00000000 | Trn mode: 0x00000010
> [ 11.391432] mmc1: sdhci: Present: 0x03ff0000 | Host ctl: 0x00000017
> [ 11.397873] mmc1: sdhci: Power: 0x0000000f | Blk gap: 0x00000000
> [ 11.404312] mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x0000000f
> [ 11.410753] mmc1: sdhci: Timeout: 0x00000004 | Int stat: 0x00000000
> [ 11.417192] mmc1: sdhci: Int enab: 0x00000020 | Sig enab: 0x00000020
> [ 11.423633] mmc1: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
> [ 11.430073] mmc1: sdhci: Caps: 0x3f69c881 | Caps_1: 0x08008177
> [ 11.436513] mmc1: sdhci: Cmd: 0x00000102 | Max curr: 0x00191919
> [ 11.442954] mmc1: sdhci: Resp[0]: 0x00000900 | Resp[1]: 0x07725f7f
> [ 11.449394] mmc1: sdhci: Resp[2]: 0x32db7900 | Resp[3]: 0x00400e00
> [ 11.455835] mmc1: sdhci: Host ctl2: 0x0000300b
> [ 11.460280] mmc1: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x0000000000882220
> [ 11.467416] mmc1: sdhci: ============================================
> [ 11.563828] mmc1: Tuning failed, falling back to fixed sampling clock
> [ 11.576053] mmc1: tuning execution failed: -5
> [ 11.646438] mmc1: new high speed SDXC card at address aaaa
> [ 11.653170] mmcblk1: mmc1:aaaa SR256 238 GiB
>
> I can write something into the SD card and read it back though. But
> this makes me reluctant to use the SD card for "some real thing" afraid
> of a data loss.
>
> The SD card is a SanDisk Extreme Pro 256GB (rated "U3, A2, V30").
>
> Any idea how to debug this issue further? (Maybe I should try change
> the SD card first but I'd like to discuss the issue before paying money
> for another card.)

Revy informed me that downclocking from 198 MHz to 100 MHz [1] has been
observed to solve this problem. Could you try the following dts patch?

Also, I have noticed the T-Head's 5.10 vendor kernel does have some
updates in sdhci-of-dwcmshc.c related to tuning. I'll look at porting
those to the upstream driving.

Thanks,
Drew

[1] https://github.com/revyos/thead-kernel/pull/62
[2] https://github.com/revyos/thead-kernel/commit/afef388b8e26f0d77f9d2261b6e57991941a213f#diff-ba729b399f3cb86d6a2503890c3626a6426c1572a54f24cd7ab3337f5fc75674

------ [cut here] --------
From db4d406fc15c76317993a39a72061d3df47e86f0 Mon Sep 17 00:00:00 2001
From: Drew Fustini <dfustini@tenstorrent.com>
Date: Sat, 2 Mar 2024 08:21:50 -0800
Subject: [PATCH] riscv: dts: thead: downgrade microSD to 100 MHz max

Downgrade max freq for microSD controller from 198 MHz to 100 MHz to
avoid timeout errors.

Signed-off-by: Drew Fustini <dfustini@tenstorrent.com>
---
arch/riscv/boot/dts/thead/th1520-lichee-module-4a.dtsi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/boot/dts/thead/th1520-lichee-module-4a.dtsi b/arch/riscv/boot/dts/thead/th1520-lichee-module-4a.dtsi
index 1365d3a512a3..d6ae671f94a9 100644
--- a/arch/riscv/boot/dts/thead/th1520-lichee-module-4a.dtsi
+++ b/arch/riscv/boot/dts/thead/th1520-lichee-module-4a.dtsi
@@ -53,6 +53,6 @@ &emmc {

&sdio0 {
bus-width = <4>;
- max-frequency = <198000000>;
+ max-frequency = <100000000>;
status = "okay";
};
--
2.34.1