V4L/DVB: ivtv: Fix ivtv_api_get_data() to avoid unneeded IO during IRQ handling

ivtv_api_get_data() was performing more PCI MMIO than needed, resulting
often in it accounting for more than half the total time spent in
ivtv_irq_handler().  Now it only reads at most 7 of the 16 mailbox data words
over the PCI bus, and in some instances only 2 or 3 data words as needed.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Andy Walls 2010-02-10 15:34:46 -03:00 committed by Mauro Carvalho Chehab
parent 00cb9f6920
commit 587808d5f5
4 changed files with 13 additions and 10 deletions

View file

@ -258,7 +258,7 @@ void ivtv_init_mpeg_decoder(struct ivtv *itv)
IVTV_ERR("ivtv_init_mpeg_decoder failed to start playback\n");
return;
}
ivtv_api_get_data(&itv->dec_mbox, IVTV_MBOX_DMA, data);
ivtv_api_get_data(&itv->dec_mbox, IVTV_MBOX_DMA, 2, data);
mem_offset = itv->dec_mem + data[1];
if ((readbytes = load_fw_direct(IVTV_DECODE_INIT_MPEG_FILENAME,

View file

@ -562,7 +562,7 @@ static void ivtv_irq_enc_dma_complete(struct ivtv *itv)
u32 data[CX2341X_MBOX_MAX_DATA];
struct ivtv_stream *s;
ivtv_api_get_data(&itv->enc_mbox, IVTV_MBOX_DMA_END, data);
ivtv_api_get_data(&itv->enc_mbox, IVTV_MBOX_DMA_END, 2, data);
IVTV_DEBUG_HI_IRQ("ENC DMA COMPLETE %x %d (%d)\n", data[0], data[1], itv->cur_dma_stream);
del_timer(&itv->dma_timer);
@ -638,7 +638,7 @@ static void ivtv_irq_dma_err(struct ivtv *itv)
u32 data[CX2341X_MBOX_MAX_DATA];
del_timer(&itv->dma_timer);
ivtv_api_get_data(&itv->enc_mbox, IVTV_MBOX_DMA_END, data);
ivtv_api_get_data(&itv->enc_mbox, IVTV_MBOX_DMA_END, 2, data);
IVTV_DEBUG_WARN("DMA ERROR %08x %08x %08x %d\n", data[0], data[1],
read_reg(IVTV_REG_DMASTATUS), itv->cur_dma_stream);
write_reg(read_reg(IVTV_REG_DMASTATUS) & 3, IVTV_REG_DMASTATUS);
@ -669,7 +669,7 @@ static void ivtv_irq_enc_start_cap(struct ivtv *itv)
struct ivtv_stream *s;
/* Get DMA destination and size arguments from card */
ivtv_api_get_data(&itv->enc_mbox, IVTV_MBOX_DMA, data);
ivtv_api_get_data(&itv->enc_mbox, IVTV_MBOX_DMA, 7, data);
IVTV_DEBUG_HI_IRQ("ENC START CAP %d: %08x %08x\n", data[0], data[1], data[2]);
if (data[0] > 2 || data[1] == 0 || data[2] == 0) {
@ -713,9 +713,9 @@ static void ivtv_irq_dec_data_req(struct ivtv *itv)
struct ivtv_stream *s;
/* YUV or MPG */
ivtv_api_get_data(&itv->dec_mbox, IVTV_MBOX_DMA, data);
if (test_bit(IVTV_F_I_DEC_YUV, &itv->i_flags)) {
ivtv_api_get_data(&itv->dec_mbox, IVTV_MBOX_DMA, 2, data);
itv->dma_data_req_size =
1080 * ((itv->yuv_info.v4l2_src_h + 31) & ~31);
itv->dma_data_req_offset = data[1];
@ -724,6 +724,7 @@ static void ivtv_irq_dec_data_req(struct ivtv *itv)
s = &itv->streams[IVTV_DEC_STREAM_TYPE_YUV];
}
else {
ivtv_api_get_data(&itv->dec_mbox, IVTV_MBOX_DMA, 3, data);
itv->dma_data_req_size = min_t(u32, data[2], 0x10000);
itv->dma_data_req_offset = data[1];
s = &itv->streams[IVTV_DEC_STREAM_TYPE_MPG];

View file

@ -369,10 +369,11 @@ int ivtv_vapi(struct ivtv *itv, int cmd, int args, ...)
}
/* This one is for stuff that can't sleep.. irq handlers, etc.. */
void ivtv_api_get_data(struct ivtv_mailbox_data *mbdata, int mb, u32 data[])
void ivtv_api_get_data(struct ivtv_mailbox_data *mbdata, int mb,
int argc, u32 data[])
{
volatile u32 __iomem *p = mbdata->mbox[mb].data;
int i;
for (i = 0; i < CX2341X_MBOX_MAX_DATA; i++)
data[i] = readl(&mbdata->mbox[mb].data[i]);
for (i = 0; i < argc; i++, p++)
data[i] = readl(p);
}

View file

@ -24,7 +24,8 @@
#define IVTV_MBOX_DMA_END 8
#define IVTV_MBOX_DMA 9
void ivtv_api_get_data(struct ivtv_mailbox_data *mbox, int mb, u32 data[]);
void ivtv_api_get_data(struct ivtv_mailbox_data *mbdata, int mb,
int argc, u32 data[]);
int ivtv_api(struct ivtv *itv, int cmd, int args, u32 data[]);
int ivtv_vapi_result(struct ivtv *itv, u32 data[CX2341X_MBOX_MAX_DATA], int cmd, int args, ...);
int ivtv_vapi(struct ivtv *itv, int cmd, int args, ...);