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authorUlf Hansson <ulf.hansson@linaro.org>2017-04-13 16:48:11 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2017-06-20 10:30:11 +0200
commit682696605c7093d2800c498c04166831e5aedf87 (patch)
tree97e6aad0dce5d5ba2356592b05587b5a99f18304 /include/linux/mmc
parente3a84267ab3184656929b4cbf03fca4d446125dd (diff)
mmc: sdio: Add API to manage SDIO IRQs from a workqueue
For hosts not supporting MMC_CAP2_SDIO_IRQ_NOTHREAD but MMC_CAP_SDIO_IRQ, the SDIO IRQs are processed from a dedicated kernel thread. For these cases, the host calls mmc_signal_sdio_irq() from its ISR to signal a new SDIO IRQ. Signaling an SDIO IRQ makes the host's ->enable_sdio_irq() callback to be invoked to temporary disable the IRQs, before the kernel thread is woken up to process it. When processing of the IRQs are completed, they are re-enabled by the kernel thread, again via invoking the host's ->enable_sdio_irq(). The observation from this, is that the execution path is being unnecessary complex, as the host driver already knows that it needs to temporary disable the IRQs before signaling a new one. Moreover, replacing the kernel thread with a work/workqueue would not only greatly simplify the code, but also make it more robust. To address the above problems, let's continue to build upon the support for MMC_CAP2_SDIO_IRQ_NOTHREAD, as it already implements SDIO IRQs to be processed without using the clumsy kernel thread and without the ping-pong calls of the host's ->enable_sdio_irq() callback for each processed IRQ. Therefore, let's add new API sdio_signal_irq(), which enables hosts to signal/process SDIO IRQs by using a work/workqueue, rather than using the kernel thread. Add also a new host callback ->ack_sdio_irq(), which the work invokes when the SDIO IRQs have been processed. This informs the host about when it shall re-enable the SDIO IRQs. Potentially, we could re-use the existing ->enable_sdio_irq() callback instead of adding a new one, however it has turned out that it's more convenient for hosts to get this information via a separate callback. Hosts that wants to use this new method to signal/process SDIO IRQs, must enable MMC_CAP2_SDIO_IRQ_NOTHREAD and implement the ->ack_sdio_irq() callback. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org>
Diffstat (limited to 'include/linux/mmc')
-rw-r--r--include/linux/mmc/host.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 21385ac0c9b1..f186b26c05a4 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -130,6 +130,7 @@ struct mmc_host_ops {
int (*get_cd)(struct mmc_host *host);
void (*enable_sdio_irq)(struct mmc_host *host, int enable);
+ void (*ack_sdio_irq)(struct mmc_host *host);
/* optional callback for HC quirks */
void (*init_card)(struct mmc_host *host, struct mmc_card *card);
@@ -358,6 +359,7 @@ struct mmc_host {
unsigned int sdio_irqs;
struct task_struct *sdio_irq_thread;
+ struct delayed_work sdio_irq_work;
bool sdio_irq_pending;
atomic_t sdio_irq_thread_abort;
@@ -428,6 +430,7 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
}
void sdio_run_irqs(struct mmc_host *host);
+void sdio_signal_irq(struct mmc_host *host);
#ifdef CONFIG_REGULATOR
int mmc_regulator_get_ocrmask(struct regulator *supply);