On Mon, 18 Jan 2016, Josh Wu wrote:
> In current code, we use a interrupt to check whether ISI reset/disable
> action is done. Actually, we also can check ISI SR to check the
> reset/disable action by polling, and it is simpler and straight forward.
>
> So this patch use isi_hw_wait_status() to check the action status. As
> the interrupt checking the status is useless, so just remove the interrupt
> & completion code.
Sorry, I'm not convinced. Switching from interrupt-driven to polling seems
counter-productive to me. Why do you want this?
Thanks
Guennadi
>
> Signed-off-by: Josh Wu <rainyfeeling@xxxxxxxxx>
> ---
>
> drivers/media/platform/soc_camera/atmel-isi.c | 59 ++++++---------------------
> 1 file changed, 13 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c
> index f0508ea..4ddc309 100644
> --- a/drivers/media/platform/soc_camera/atmel-isi.c
> +++ b/drivers/media/platform/soc_camera/atmel-isi.c
> @@ -12,7 +12,6 @@
> */
>
> #include <linux/clk.h>
> -#include <linux/completion.h>
> #include <linux/delay.h>
> #include <linux/fs.h>
> #include <linux/init.h>
> @@ -81,7 +80,6 @@ struct atmel_isi {
> struct isi_dma_desc dma_desc[MAX_BUFFER_NUM];
> bool enable_preview_path;
>
> - struct completion complete;
> /* ISI peripherial clock */
> struct clk *pclk;
> unsigned int irq;
> @@ -281,51 +279,14 @@ static irqreturn_t isi_interrupt(int irq, void *dev_id)
> mask = isi_readl(isi, ISI_INTMASK);
> pending = status & mask;
>
> - if (pending & ISI_CTRL_SRST) {
> - complete(&isi->complete);
> - isi_writel(isi, ISI_INTDIS, ISI_CTRL_SRST);
> - ret = IRQ_HANDLED;
> - } else if (pending & ISI_CTRL_DIS) {
> - complete(&isi->complete);
> - isi_writel(isi, ISI_INTDIS, ISI_CTRL_DIS);
> - ret = IRQ_HANDLED;
> - } else {
> - if (likely(pending & ISI_SR_CXFR_DONE) ||
> - likely(pending & ISI_SR_PXFR_DONE))
> - ret = atmel_isi_handle_streaming(isi);
> - }
> + if (likely(pending & ISI_SR_CXFR_DONE) ||
> + likely(pending & ISI_SR_PXFR_DONE))
> + ret = atmel_isi_handle_streaming(isi);
>
> spin_unlock(&isi->lock);
> return ret;
> }
>
> -#define WAIT_ISI_RESET 1
> -#define WAIT_ISI_DISABLE 0
> -static int atmel_isi_wait_status(struct atmel_isi *isi, int wait_reset)
> -{
> - unsigned long timeout;
> - /*
> - * The reset or disable will only succeed if we have a
> - * pixel clock from the camera.
> - */
> - init_completion(&isi->complete);
> -
> - if (wait_reset) {
> - isi_writel(isi, ISI_INTEN, ISI_CTRL_SRST);
> - isi_writel(isi, ISI_CTRL, ISI_CTRL_SRST);
> - } else {
> - isi_writel(isi, ISI_INTEN, ISI_CTRL_DIS);
> - isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
> - }
> -
> - timeout = wait_for_completion_timeout(&isi->complete,
> - msecs_to_jiffies(500));
> - if (timeout == 0)
> - return -ETIMEDOUT;
> -
> - return 0;
> -}
> -
> /* ------------------------------------------------------------------
> Videobuf operations
> ------------------------------------------------------------------*/
> @@ -493,8 +454,11 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
> pm_runtime_get_sync(ici->v4l2_dev.dev);
>
> /* Reset ISI */
> - ret = atmel_isi_wait_status(isi, WAIT_ISI_RESET);
> - if (ret < 0) {
> + isi_writel(isi, ISI_CTRL, ISI_CTRL_SRST);
> +
> + /* Check Reset status */
> + ret = isi_hw_wait_status(isi, ISI_CTRL_SRST, 500);
> + if (ret) {
> dev_err(icd->parent, "Reset ISI timed out\n");
> pm_runtime_put(ici->v4l2_dev.dev);
> return ret;
> @@ -549,8 +513,11 @@ static void stop_streaming(struct vb2_queue *vq)
> ISI_SR_CXFR_DONE | ISI_SR_PXFR_DONE);
>
> /* Disable ISI and wait for it is done */
> - ret = atmel_isi_wait_status(isi, WAIT_ISI_DISABLE);
> - if (ret < 0)
> + isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
> +
> + /* Check Reset status */
> + ret = isi_hw_wait_status(isi, ISI_CTRL_DIS, 500);
> + if (ret)
> dev_err(icd->parent, "Disable ISI timed out\n");
>
> pm_runtime_put(ici->v4l2_dev.dev);
> --
> 1.9.1
>
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