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

[Xi Ruoyao]

On Sat, 2024-03-02 at 08:25 -0800, Drew Fustini wrote:
> 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?

I'm still getting the same error.

> 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.

Maybe to solve the problem we need both the downclocking and these
changes then...

-- 
Xi Ruoyao <xry111 at xry111.site>
School of Aerospace Science and Technology, Xidian University