Re: [PATCH v5 0/2] mmc: litex_mmc: Set mandatory idle clocks before CMD0

[Ulf Hansson]

On Thu, May 21, 2026 at 9:21 AM Inochi Amaoto <inochiama@xxxxxxxxx> wrote:
>
> The litex_mmc driver assumes the card is already probed in the BIOS
> and skip the phy initialization. This will cause the command fail
> like the following when the old card is unplugged and then insert
> a new card:
>
> [   62.923593] litex-mmc f0004000.mmc: Command (cmd 8) error, status -110
> [   62.949717] litex-mmc f0004000.mmc: Command (cmd 55) error, status -110
> [   62.976606] litex-mmc f0004000.mmc: Command (cmd 55) error, status -110
> [   63.002516] litex-mmc f0004000.mmc: Command (cmd 55) error, status -110
> [   63.028442] litex-mmc f0004000.mmc: Command (cmd 55) error, status -110
>
> Firstly, fix the clock divider calculation so we can get the right
> clock frequency, then add required clock settings and initialization
> for the CMD 0, so it can probe the new card.
>
> Test Results:
> Rocket:
> # dmesg | grep mmc
> [    0.109176] litex-mmc 12003000.mmc: LiteX MMC controller initialized.
> [    0.256926] mmc0: new SDHC card at address aaaa
> [    0.257058] mmcblk0: mmc0:aaaa WC32G 29.7 GiB
>
> Note: it seems like the rocket give a wrong DMA result when the target
> address is in main memory.
> See issue: https://github.com/enjoy-digital/litex/issues/2464
>
> VexiiRiscv:
> # dmesg | grep mmc
> [    2.368365] litex-mmc f0004000.mmc: LiteX MMC controller initialized.
> [    2.576993] mmc0: new SDHC card at address aaaa
> [    2.588966] mmcblk0: mmc0:aaaa WC32G 29.7 GiB
> [    2.620197]  mmcblk0: p1
>
> Changed from v4:
> - https://lore.kernel.org/linux-mmc/20260517015323.264179-1-inochiama@xxxxxxxxx/
> 1. Add a new patch for fixing clock divider calculation
> 2. Move everything in the set_ios() callback.
>
> Changed from v3:
> - https://lore.kernel.org/linux-mmc/20260426112016.1370929-1-inochiama@xxxxxxxxx/
> 1. Remove patch 1: mmc: litex_mmc: Move litex_mmc_setclk() to bottom for reuse
> 2. Use set_ios() callback to apply the clock change.
>
> Changed from v2:
> - https://lore.kernel.org/linux-mmc/20260424013615.470325-1-inochiama@xxxxxxxxx/
> 1. Remove the added function forward reference and add a new patch
>    for moving litex_mmc_setclk() function
>
> Change from v1:
> - https://lore.kernel.org/linux-mmc/20260421025052.755471-1-inochiama@xxxxxxxxx/
> 1. use fsleep to replace udelay
>
> Inochi Amaoto (2):
>   mmc: litex_mmc: Use DIV_ROUND_UP for more accurate clock calculation
>   mmc: litex_mmc: Set mandatory idle clocks before CMD0
>
>  drivers/mmc/host/litex_mmc.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
>
> --
> 2.54.0

The series applied for fixes and by adding stable tags to both patches, thanks!

Kind regards
Uffe