Re: [PATCH v15 01/12] media: mediatek: jpeg: fix jpeg cores' amounts setting

["Kyrie Wu (吴晗)" <Kyrie.Wu@mediatek.com>]

On Sat, 2026-07-11 at 17:43 -0400, Nicolas Dufresne wrote:
> Hi,
> 
> Le jeudi 02 juillet 2026 à 15:26 +0800, Kyrie Wu a écrit :
> > Different ICs have different amounts of cores,
> > use a variable to set the cores' amounts.
> > 
> > Fixes: 934e8bccac95 ("mtk-jpegenc: support jpegenc multi-hardware")
> > Fixes: 0fa49df4222f ("media: mtk-jpegdec: support jpegdec multi-
> > hardware")
> > Signed-off-by: Kyrie Wu <kyrie.wu@mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno
> > <angelogioacchino.delregno@collabora.com>
> > ---
> >  drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c   | 8 ++++---
> > -
> >  drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.h   | 2 ++
> >  drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_hw.c | 1 +
> >  drivers/media/platform/mediatek/jpeg/mtk_jpeg_enc_hw.c | 1 +
> >  4 files changed, 8 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > index d147ec483081..1e014fd698ae 100644
> > --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> > @@ -1462,7 +1462,7 @@ static int mtk_jpegenc_get_hw(struct
> > mtk_jpeg_ctx *ctx)
> >  	int i;
> >  
> >  	spin_lock_irqsave(&jpeg->hw_lock, flags);
> > -	for (i = 0; i < MTK_JPEGENC_HW_MAX; i++) {
> > +	for (i = 0; i < jpeg->max_hw_count; i++) {
> >  		comp_jpeg = jpeg->enc_hw_dev[i];
> >  		if (comp_jpeg->hw_state == MTK_JPEG_HW_IDLE) {
> >  			hw_id = i;
> > @@ -1509,7 +1509,7 @@ static int mtk_jpegdec_get_hw(struct
> > mtk_jpeg_ctx *ctx)
> >  	int i;
> >  
> >  	spin_lock_irqsave(&jpeg->hw_lock, flags);
> > -	for (i = 0; i < MTK_JPEGDEC_HW_MAX; i++) {
> > +	for (i = 0; i < jpeg->max_hw_count; i++) {
> >  		comp_jpeg = jpeg->dec_hw_dev[i];
> >  		if (comp_jpeg->hw_state == MTK_JPEG_HW_IDLE) {
> >  			hw_id = i;
> > @@ -1592,7 +1592,7 @@ static void mtk_jpegenc_worker(struct
> > work_struct *work)
> >  		jpeg_work);
> >  	struct mtk_jpeg_dev *jpeg = ctx->jpeg;
> >  
> > -	for (i = 0; i < MTK_JPEGENC_HW_MAX; i++)
> > +	for (i = 0; i < jpeg->max_hw_count; i++)
> >  		comp_jpeg[i] = jpeg->enc_hw_dev[i];
> >  	i = 0;
> >  
> > @@ -1687,7 +1687,7 @@ static void mtk_jpegdec_worker(struct
> > work_struct *work)
> >  	struct mtk_jpeg_fb fb;
> >  	unsigned long flags;
> >  
> > -	for (i = 0; i < MTK_JPEGDEC_HW_MAX; i++)
> > +	for (i = 0; i < jpeg->max_hw_count; i++)
> >  		comp_jpeg[i] = jpeg->dec_hw_dev[i];
> >  	i = 0;
> >  
> > diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.h
> > b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.h
> > index 02ed0ed5b736..6be5cf30dea1 100644
> > --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.h
> > +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.h
> > @@ -212,6 +212,7 @@ struct mtk_jpegdec_comp_dev {
> >   * @reg_decbase:	jpg decode register base addr
> >   * @dec_hw_dev:	jpg decode hardware device
> >   * @hw_index:		jpg hw index
> > + * @max_hw_count:	jpeg hw-core count
> >   */
> >  struct mtk_jpeg_dev {
> >  	struct mutex		lock;
> > @@ -234,6 +235,7 @@ struct mtk_jpeg_dev {
> >  	void __iomem *reg_decbase[MTK_JPEGDEC_HW_MAX];
> >  	struct mtk_jpegdec_comp_dev
> > *dec_hw_dev[MTK_JPEGDEC_HW_MAX];
> >  	atomic_t hw_index;
> > +	u32 max_hw_count;
> >  };
> >  
> >  /**
> > diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_hw.c
> > b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_hw.c
> > index 32372781daf5..4534caeb104f 100644
> > --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_hw.c
> > +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_dec_hw.c
> > @@ -664,6 +664,7 @@ static int mtk_jpegdec_hw_probe(struct
> > platform_device *pdev)
> >  	master_dev->dec_hw_dev[i] = dev;
> >  	master_dev->reg_decbase[i] = dev->reg_base;
> >  	dev->master_dev = master_dev;
> > +	master_dev->max_hw_count++;
> 
> Just one question, can the mtk_jpegenc_worker() starts before all
> cores have
> been probed ?
> 
> Nicolas

Dear Nicolas,

Thanks for the question.

mtk_jpegenc_worker() is not started from the probe path. For the
multicore encoder, the worker is only initialized when userspace
opens the video node:
    mtk_jpeg_open()
      INIT_WORK(&ctx->jpeg_work, jpeg->variant->jpeg_worker)

It is then queued only through the V4L2 mem2mem run path:
    userspace QBUF/STREAMON
      -> v4l2_m2m_try_schedule()
      -> .device_run = mtk_jpeg_multicore_enc_device_run()
      -> queue_work(jpeg->workqueue, &ctx->jpeg_work)
      -> mtk_jpegenc_worker()

So the worker can run only after the video device has been registered 
and after a userspace application opens the device and starts
streaming buffers.

The JPEG hw core probe is part of the platform device probe flow during
system boot. The userspace open/streaming path happens later, after the
system has booted and the video node is available. Therefore we do not
have a case where mtk_jpegenc_worker() starts before the JPEG hw probe
has completed.

Regards,
Kyrie.
> 
> >  
> >  	platform_set_drvdata(pdev, dev);
> >  	pm_runtime_enable(&pdev->dev);
> > diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_enc_hw.c
> > b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_enc_hw.c
> > index b6f5b2249f1f..2765dafab4ad 100644
> > --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_enc_hw.c
> > +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_enc_hw.c
> > @@ -386,6 +386,7 @@ static int mtk_jpegenc_hw_probe(struct
> > platform_device *pdev)
> >  	master_dev->enc_hw_dev[i] = dev;
> >  	master_dev->reg_encbase[i] = dev->reg_base;
> >  	dev->master_dev = master_dev;
> > +	master_dev->max_hw_count++;
> >  
> >  	platform_set_drvdata(pdev, dev);
> >  	pm_runtime_enable(&pdev->dev);