Jaehoon,
On Fri, Oct 18, 2013 at 2:42 AM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
>> - clk_en_a = mci_readl(host, CLKENA);
>> + /*
>> + * Low power mode will stop the card clock when idle. According to the
>> + * description of the CLKENA register we should disable low power mode
>> + * for SDIO cards if we need SDIO interrupts to work.
>> + */
>> + if (mmc->caps | MMC_CAP_SDIO_IRQ) {
> mmc->caps & MMC_CAP_SDIO_IRQ?
Wow, that was an embarrassing one. Thanks.
>> + const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
>> + u32 clk_en_a_old;
>> + u32 clk_en_a;
>>
>> - if (clk_en_a & clken_low_pwr) {
>> - mci_writel(host, CLKENA, clk_en_a & ~clken_low_pwr);
>> - mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
>> - SDMMC_CMD_PRV_DAT_WAIT, 0);
>> + clk_en_a_old = mci_readl(host, CLKENA);
>> +
>> + if (card->type == MMC_TYPE_SDIO ||
>> + card->type == MMC_TYPE_SD_COMBO) {
>> + set_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags);
>> + clk_en_a = clk_en_a_old & ~clken_low_pwr;
>> + } else {
>> + clear_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags);
>> + clk_en_a = clk_en_a_old | clken_low_pwr;
> When this condition is entered? card->type is always MMC_TYPE_SDIO or MMC_TYPE_SD_COMBO, isn't?
Ugh, that's not intuitive. This callback is only called for SDIO
cards and not MMC/SD cards? That means if you plug in an SDIO card
and then eject it and plug in an SD card you won't get to low power.
Hrm.
I dug around a bit and couldn't find a better way to do this and then
I realized that the other user of the init_card() callback has the
same bug, so for the next version of the series I'm proposing a fix
for mmc core to add this for all types. If you have a better
suggestion, I'm all ears.
-Doug
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