Hello,
On 17 August 2015 at 03:55, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
> Hi, Michal.
>
> On 08/12/2015 09:23 PM, Michal Suchanek wrote:
>> The driver has open-coded test for SDIO cards. Use the mmc core provided
>> MMC_QUIRK_BROKEN_CLK_GATING flag instead.
>
> Did you use the clock-gating for SDIO cards?
> Doesn't MMC_CAP_SDIO_IRQ bit set? Which case is broken?
> Could you explain to me more?
The core flag for disabling power saving is MMC_QUIRK_BROKEN_CLK_GATING.
It may coincide with MMC_CAP_SDIO_IRQ but that's different flag for
different purpose.
MMC_QUIRK_BROKEN_CLK_GATING is currently set for all SDIO cards except
for cards on a whitelist.
I don't know any particular SDIO card that has problems when the clock
is off and does not use an IRQ.
Thanks
Michal
>
> Best Regards,
> Jaehoon Chung
>
>>
>> As a bonus this may enable clock gating on SDIO cards that are known to
>> work with it.
>>
>> Signed-off-by: Michal Suchanek <hramrach@xxxxxxxxx>
>> ---
>> drivers/mmc/host/dw_mmc.c | 33 +++++++++++++++------------------
>> 1 file changed, 15 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 40e9d8e..3bc9fd7 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -1335,27 +1335,24 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
>> * 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) {
>> - const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
>> - u32 clk_en_a_old;
>> - u32 clk_en_a;
>> + const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
>> + u32 clk_en_a_old;
>> + u32 clk_en_a;
>>
>> - clk_en_a_old = mci_readl(host, CLKENA);
>> + 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;
>> - }
>> + if (card->quirks & MMC_QUIRK_BROKEN_CLK_GATING) {
>> + 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;
>> + }
>>
>> - if (clk_en_a != clk_en_a_old) {
>> - mci_writel(host, CLKENA, clk_en_a);
>> - mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
>> - SDMMC_CMD_PRV_DAT_WAIT, 0);
>> - }
>> + if (clk_en_a != clk_en_a_old) {
>> + mci_writel(host, CLKENA, clk_en_a);
>> + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
>> + SDMMC_CMD_PRV_DAT_WAIT, 0);
>> }
>> }
>>
>>
>
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