[PATCH v2] mmc: meson-mx-sdhc: Fix initialization frozen issue

[Ziyang Huang]

在 2023/10/29 21:08, Anand Moon 写道:
> Hi Ziyang,
> 
> On Tue, 10 Oct 2023 at 22:15, Ziyang Huang <hzyitc at outlook.com> wrote:
>>
>> Commit 4bc31edebde5 ("mmc: core: Set HS clock speed before sending
>> HS CMD13") set HS clock (52MHz) before switching to HS mode. For this
>> freq, FCLK_DIV5 will be selected and div value is 10 (reg value is 9).
>> Then we set rx_clk_phase to 11 or 15 which is out of range and make
>> hardware frozen. After we send command request, no irq will be
>> interrupted and the mmc driver will keep to wait for request finished,
>> even durning rebooting.
>>
>> So let's set it to Phase 90 which should work in most cases. Then let
>> meson_mx_sdhc_execute_tuning() to find the accurate value for data
>> transfer.
>>
>> If this doesn't work, maybe need to define a factor in dts.
>>
>> Fixes: e4bf1b0970ef ("mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host")
>> Signed-off-by: Ziyang Huang <hzyitc at outlook.com>
>> ---
>> Changes since v1:
>>    Use Phase 90 instand of value 1
>>
> 
> I have tested this patch on my Odroid C1+ board.
> Please add my
> 
> Tested-by: Anand Moon <linux.amoon at gmail.com>
> 
> [alarm at alarm ~]$ sudo cat /sys/kernel/debug/mmc1/ios
> clock:          100000000 Hz
> actual clock:   94444445 Hz
> vdd:            21 (3.3 ~ 3.4 V)
> bus mode:       2 (push-pull)
> chip select:    0 (don't care)
> power mode:     2 (on)
> bus width:      3 (8 bits)
> timing spec:    9 (mmc HS200)
> signal voltage: 1 (1.80 V)
> driver type:    0 (driver type B)
> [alarm at alarm ~]$ sync && dd if=/dev/zero of=~/testfile bs=100M count=1
> oflag=dsync && sync
> 1+0 records in
> 1+0 records out
> 104857600 bytes (105 MB, 100 MiB) copied, 5.70235 s, 18.4 MB/s
> [alarm at alarm ~]$ sync && dd if=~/testfile of=/dev/null bs=100M count=1
> iflag=dsync && sync
> 1+0 records in
> 1+0 records out
> 104857600 bytes (105 MB, 100 MiB) copied, 0.20267 s, 517 MB/s
> 
> Thanks
> -Anand
> 

Oh, thank you.