[AMD Official Use Only - General] Hi Felix, Yes, I just realized ffs start counting from 1. Sorry for the noise. Best Regards, Yifan -----Original Message----- From: Kuehling, Felix <Felix.Kuehling@xxxxxxx> Sent: Friday, September 30, 2022 10:55 PM To: Zhang, Yifan <Yifan1.Zhang@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Ji, Ruili <Ruili.Ji@xxxxxxx> Subject: Re: [PATCH 1/2] drm/amdkfd: correct RB_SIZE in SDMA0_QUEUE0_RB_CNTL Am 2022-09-30 um 02:16 schrieb Yifan Zhang: > In SDMA0_QUEUE0_RB_CNTL, queue size is 2^RB_SIZE, not 2^(RB_SIZE +1). > > Signed-off-by: Yifan Zhang <yifan1.zhang@xxxxxxx> > --- > drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v10.c | 2 +- > drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v11.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v10.c > b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v10.c > index d3e2b6a599a4..03699a9ad3d9 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v10.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v10.c > @@ -329,7 +329,7 @@ static void update_mqd_sdma(struct mqd_manager *mm, void *mqd, > struct v10_sdma_mqd *m; > > m = get_sdma_mqd(mqd); > - m->sdmax_rlcx_rb_cntl = (ffs(q->queue_size / sizeof(unsigned int)) - 1) > + m->sdmax_rlcx_rb_cntl = order_base_2(q->queue_size / 4) I think these two are equivalent. ffs(1) == 1. order_base_2(1) == 0. You're not correcting anything. You're just writing it differently. Regards, Felix > << SDMA0_RLC0_RB_CNTL__RB_SIZE__SHIFT | > q->vmid << SDMA0_RLC0_RB_CNTL__RB_VMID__SHIFT | > 1 << SDMA0_RLC0_RB_CNTL__RPTR_WRITEBACK_ENABLE__SHIFT | diff --git > a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v11.c > b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v11.c > index 26b53b6d673e..451fcb9bb051 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v11.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v11.c > @@ -329,7 +329,7 @@ static void update_mqd_sdma(struct mqd_manager *mm, void *mqd, > struct v11_sdma_mqd *m; > > m = get_sdma_mqd(mqd); > - m->sdmax_rlcx_rb_cntl = (ffs(q->queue_size / sizeof(unsigned int)) - 1) > + m->sdmax_rlcx_rb_cntl = order_base_2(q->queue_size / 4) > << SDMA0_QUEUE0_RB_CNTL__RB_SIZE__SHIFT | > q->vmid << SDMA0_QUEUE0_RB_CNTL__RB_VMID__SHIFT | > 1 << SDMA0_QUEUE0_RB_CNTL__RPTR_WRITEBACK_ENABLE__SHIFT |
