RE: [PATCH v7][2/4] mmc: Add Synopsys DesignWare mmc cmdq host driver

Jyan Chou [周芷安]
2023-12-11T10:39:55Z

Hi Adrian,

>>>> +
>>>> +static irqreturn_t dw_mci_cqe_interrupt(int irq, void *dev_id) {
>>>> + struct dw_mci *host = dev_id;
>>>> + struct mmc_host *mmc = host->slot->mmc;
>>>> + struct cqhci_host *cq_host = NULL;
>>>> + int cmd_error = 0, data_error = 0;
>>>> +
>>>> + if (host->pdata && (host->pdata->caps2 & MMC_CAP2_CQE))
>>>> + cq_host = mmc->cqe_private;
>>>> +
>>>> + dw_mci_get_int(host);
>>>> +
>>>> + if (host->pdata && (host->pdata->caps2 & MMC_CAP2_CQE)) {
>>>> + if (!mmc->cqe_on && !cq_host->activated)
>>>
>>> Shouldn't really look at internals like mmc->cqe_on or cq_host->activated.
>>> There are the cqhci_host_ops ->enable() and ->disable() callbacks to
>>> keep track of whether cqhci is expecting interrupts.
>>
>> Does this means we need to use cqhci_host_ops ->enable() and
>> ->disable() callbacks instead of mmc->cqe_on && !cq_host->activated?
>Thanks.
>
>Yes. ->enable() is always called before cqhci operation and ->disable() before
>non-cqhci operation, so they can be used to determine if an interrupt is for
>cqhci.

Thanks for your advice, and I got your point for calling cqhci_host_ops ->enable()

and ->disable() callbacks, but the reason we used " if (!mmc->cqe_on && !cq_host->activated) "

is that when sending command like cmd0, 1, 7, 8... in mmc_init_card before mmc_cmdq_enable,

we need to use interrupt in legacy mode, it is much better to write in this way?

+ events = mci_readw(host, NORMAL_INT_STAT_R);
- if (host->pdata && (host->pdata->caps2 & MMC_CAP2_CQE)) {
- if (!mmc->cqe_on && !cq_host->activated)
+ if (mmc->caps2 & MMC_CAP2_CQE) {
+ if (!(events & CQE_EVENT))
dw_mci_clr_signal_int(host);

Using CQE_EVENT to determine whether Command Queue enable or not.

Many thanks.

Best Regards,
Jyan