RE: [PATCH] mmc: print clock frequency with recognization

From: Seunghui Lee
Date: Mon Jul 11 2022 - 20:08:24 EST


> -----Original Message-----
> From: Seunghui Lee <sh043.lee@xxxxxxxxxxx>
> Sent: Tuesday, July 5, 2022 9:51 AM
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> gregkh@xxxxxxxxxxxxxxxxxxx; linux@xxxxxxxxxxxxxxxxxxxx;
> alexandre.belloni@xxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; linux-
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> seunghwan.hyun@xxxxxxxxxxx; Seunghui Lee <sh043.lee@xxxxxxxxxxx>
> Subject: [PATCH] mmc: print clock frequency with recognization
>
> It's easy to figure out how fast frequency it has from the log.
> e.g. mmc0: new ultra high speed SDR104 SDXC card at address aaaa(clk
> 202000000)
>
> Signed-off-by: Seunghui Lee <sh043.lee@xxxxxxxxxxx>
> ---
> drivers/mmc/core/bus.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c index
> 58a60afa650b..3623cc27a61c 100644
> --- a/drivers/mmc/core/bus.c
> +++ b/drivers/mmc/core/bus.c
> @@ -348,7 +348,7 @@ int mmc_add_card(struct mmc_card *card)
> mmc_card_ddr52(card) ? "DDR " : "",
> type);
> } else {
> - pr_info("%s: new %s%s%s%s%s%s card at address %04x\n",
> + pr_info("%s: new %s%s%s%s%s%s card at
> address %04x(clk %u)\n",
> mmc_hostname(card->host),
> mmc_card_uhs(card) ? "ultra high speed " :
> (mmc_card_hs(card) ? "high speed " : ""), @@ -356,7
> +356,8 @@ int mmc_add_card(struct mmc_card *card)
> (mmc_card_hs200(card) ? "HS200 " : ""),
> mmc_card_hs400es(card) ? "Enhanced strobe " : "",
> mmc_card_ddr52(card) ? "DDR " : "",
> - uhs_bus_speed_mode, type, card->rca);
> + uhs_bus_speed_mode, type, card->rca,
> + card->host->ios.clock);
> }
>
> #ifdef CONFIG_DEBUG_FS
> --
> 2.29.0
Please give me any opinion or suggestion about this commit.
Normally, the SD card's bus speed depends on both host controller and internal PLL.
There are lots of host controller vendor in the market as well.
So, we can guess the exact clock speed from this commit.