Re: [RFC PATCH v5 1/9] mmc: dw_mmc: Add external dma interface support

From: Shawn Lin
Date: Mon Aug 17 2015 - 02:28:10 EST

å 2015/8/17 5:10, Doug Anderson åé:
Heiko,

On Fri, Aug 14, 2015 at 3:13 PM, Heiko StÃbner <heiko@xxxxxxxxx> wrote:
Hi Shawn,

Am Freitag, 14. August 2015, 16:34:35 schrieb Shawn Lin:
DesignWare MMC Controller can supports two types of DMA
mode: external dma and internal dma. We get a RK312x platform
integrated dw_mmc and ARM pl330 dma controller. This patch add
edmac ops to support these platforms. I've tested it on RK312x
platform with edmac mode and RK3288 platform with idmac mode.

Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

judging by your "from", I guess you're running this on some older Rockchip soc
without the idma? Because I tried testing this on a Radxa Rock, but only got
failures, from the start (failed to read card status register). In PIO mode
everything works again.


I guess I overlooked just some tiny detail, but to me the dma channel ids seem
correct after all. Maybe you have any hints what I'm doing wrong?

If I were a guessing man (which I'm not), I'd guess that perhaps
you're running into troubles with our friend the PL330.

There appear to be strange issues with the PL330 on Rockchip SoCs. I
was only peripherally involved with them, but I know at least about
some of the patches in our tree, like:


Thanks, Doug, that's the root cause. PL330 on Rockchip Socs need your patches, and we might need another patch to limit pl330 burst_len to 16(Hmm...seems another quirks for rockchip but not on your tree);

Hi Heiko,
I just get a Radxa Rock luckily and test my patch based on http://radxa.com/Rock/Linux_Mainline. Yes, it can't work.

If you test my patchset on Rockchip platform, pls apply pl330 patch from my tree based on kernel 4.2-RC3. AND, temporary hack dw_mmc to limit pl330 burst_len to 16.
This is a dmaengine or pl330 problem(I guest it should be upstreamed later?), but my patchset is for *generic* dw_mmc to support emdac, so other platforms should never need the hack of pl330.

pl330.patch is for pl330 changes
r3xxx.patch is for pl330 quirks

AND pls limit burst_len to 16 for BROKRN pl330 of rockchips.
static int dw_mci_edmac_start_dma(
...
+ u32 burst_limit = 0;
+ u32 mburst;
+ u32 idx, rx_wmark, tx_wmark;

...
/* Match burst msize with external dma config */
fifoth_val = mci_readl(host, FIFOTH);
- cfg.dst_maxburst = mszs[(fifoth_val >> 28) & 0x7];
- cfg.src_maxburst = cfg.dst_maxburst;
+ /* HACK for BROKEN pl330 */
+ mburst = mszs[(fifoth_val >> 28) & 0x7];
+ burst_limit = 16;
+ if (mburst > burst_limit) {
+ mburst = burst_limit;
+ idx = (ilog2(mburst) > 0) ? (ilog2(mburst) - 1) : 0;
+ rx_wmark = mszs[idx] - 1;
+ tx_wmark = (host->fifo_depth) / 2;
+ fifoth_val = SDMMC_SET_FIFOTH(idx, rx_wmark, tx_wmark);
+ mci_writel(host, FIFOTH, fifoth_val);
+ }
+ cfg.dst_maxburst = mburst;
+ cfg.src_maxburst = cfg.dst_maxburst;


https://chromium-review.googlesource.com/237607
FROMLIST: DMA: pl330: support burst mode for dev-to-mem and mem-to-dev transmit

https://chromium-review.googlesource.com/237393
CHROMIUM: dmaengine: pl330: support quirks for some broken

https://chromium-review.googlesource.com/237396
CHROMIUM: dmaengine: pl330: add quirk for broken no flushp

https://chromium-review.googlesource.com/237394
CHROMIUM: ARM: dts: rockchip: Add broken-no-flushp into rk3288.dtsi

https://chromium-review.googlesource.com/242063
CHROMIUM: ASoC: rockchip_i2s: modify DMA max burst to 1





--
Shawn Lin
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index ecab4ea..b2a950c 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -34,6 +34,14 @@
#define PL330_MAX_IRQS 32
#define PL330_MAX_PERI 32

+#define PL330_QUIRK_BROKEN_NO_FLUSHP BIT(0)
+
+enum pl330_cond {
+ SINGLE,
+ BURST,
+ ALWAYS,
+};
+
enum pl330_cachectrl {
CCTRL0, /* Noncacheable and nonbufferable */
CCTRL1, /* Bufferable only */
@@ -344,12 +352,6 @@ enum pl330_dst {
DST,
};

-enum pl330_cond {
- SINGLE,
- BURST,
- ALWAYS,
-};
-
struct dma_pl330_desc;

struct _pl330_req {
@@ -488,6 +490,17 @@ struct pl330_dmac {
/* Peripheral channels connected to this DMAC */
unsigned int num_peripherals;
struct dma_pl330_chan *peripherals; /* keep at end */
+ int quirks;
+};
+
+static struct pl330_of_quirks {
+ char *quirk;
+ int id;
+} of_quirks[] = {
+ {
+ .quirk = "broken-no-flushp",
+ .id = PL330_QUIRK_BROKEN_NO_FLUSHP,
+ }
};

struct dma_pl330_desc {
@@ -1137,47 +1150,64 @@ static inline int _ldst_memtomem(unsigned dry_run, u8 buf[],
return off;
}

-static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
+static inline int _ldst_devtomem(struct pl330_dmac *pi,unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
+ enum pl330_cond cond;
+
+ if (pi->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
+ cond = BURST;
+ else
+ cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;

while (cyc--) {
- off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
- off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
+ off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
+ off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_ST(dry_run, &buf[off], ALWAYS);
- off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
+
+ if (!(pi->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
+ off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
}

return off;
}

-static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
+static inline int _ldst_memtodev(struct pl330_dmac *pi, unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
+ enum pl330_cond cond;
+
+ if (pi->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
+ cond = BURST;
+ else
+ cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
+

while (cyc--) {
- off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
+ off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_LD(dry_run, &buf[off], ALWAYS);
- off += _emit_STP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
- off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
+ off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri);
+
+ if (!(pi->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
+ off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
}

return off;
}

-static int _bursts(unsigned dry_run, u8 buf[],
+static int _bursts(struct pl330_dmac *pi,unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;

switch (pxs->desc->rqtype) {
case DMA_MEM_TO_DEV:
- off += _ldst_memtodev(dry_run, &buf[off], pxs, cyc);
+ off += _ldst_memtodev(pi, dry_run, &buf[off], pxs, cyc);
break;
case DMA_DEV_TO_MEM:
- off += _ldst_devtomem(dry_run, &buf[off], pxs, cyc);
+ off += _ldst_devtomem(pi, dry_run, &buf[off], pxs, cyc);
break;
case DMA_MEM_TO_MEM:
off += _ldst_memtomem(dry_run, &buf[off], pxs, cyc);
@@ -1191,7 +1221,7 @@ static int _bursts(unsigned dry_run, u8 buf[],
}

/* Returns bytes consumed and updates bursts */
-static inline int _loop(unsigned dry_run, u8 buf[],
+static inline int _loop(struct pl330_dmac *pi, unsigned dry_run, u8 buf[],
unsigned long *bursts, const struct _xfer_spec *pxs)
{
int cyc, cycmax, szlp, szlpend, szbrst, off;
@@ -1214,7 +1244,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
}

szlp = _emit_LP(1, buf, 0, 0);
- szbrst = _bursts(1, buf, pxs, 1);
+ szbrst = _bursts(pi, 1, buf, pxs, 1);

lpend.cond = ALWAYS;
lpend.forever = false;
@@ -1246,7 +1276,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
off += _emit_LP(dry_run, &buf[off], 1, lcnt1);
ljmp1 = off;

- off += _bursts(dry_run, &buf[off], pxs, cyc);
+ off += _bursts(pi, dry_run, &buf[off], pxs, cyc);

lpend.cond = ALWAYS;
lpend.forever = false;
@@ -1269,7 +1299,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
return off;
}

-static inline int _setup_loops(unsigned dry_run, u8 buf[],
+static inline int _setup_loops(struct pl330_dmac *pi, unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs)
{
struct pl330_xfer *x = &pxs->desc->px;
@@ -1279,14 +1309,14 @@ static inline int _setup_loops(unsigned dry_run, u8 buf[],

while (bursts) {
c = bursts;
- off += _loop(dry_run, &buf[off], &c, pxs);
+ off += _loop(pi, dry_run, &buf[off], &c, pxs);
bursts -= c;
}

return off;
}

-static inline int _setup_xfer(unsigned dry_run, u8 buf[],
+static inline int _setup_xfer(struct pl330_dmac *pi,unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs)
{
struct pl330_xfer *x = &pxs->desc->px;
@@ -1298,7 +1328,7 @@ static inline int _setup_xfer(unsigned dry_run, u8 buf[],
off += _emit_MOV(dry_run, &buf[off], DAR, x->dst_addr);

/* Setup Loop(s) */
- off += _setup_loops(dry_run, &buf[off], pxs);
+ off += _setup_loops(pi, dry_run, &buf[off], pxs);

return off;
}
@@ -1307,7 +1337,7 @@ static inline int _setup_xfer(unsigned dry_run, u8 buf[],
* A req is a sequence of one or more xfer units.
* Returns the number of bytes taken to setup the MC for the req.
*/
-static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
+static int _setup_req(struct pl330_dmac *pi,unsigned dry_run, struct pl330_thread *thrd,
unsigned index, struct _xfer_spec *pxs)
{
struct _pl330_req *req = &thrd->req[index];
@@ -1325,7 +1355,7 @@ static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
return -EINVAL;

- off += _setup_xfer(dry_run, &buf[off], pxs);
+ off += _setup_xfer(pi, dry_run, &buf[off], pxs);

/* DMASEV peripheral/event */
off += _emit_SEV(dry_run, &buf[off], thrd->ev);
@@ -1419,7 +1449,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
xs.desc = desc;

/* First dry run to check if req is acceptable */
- ret = _setup_req(1, thrd, idx, &xs);
+ ret = _setup_req(pl330, 1, thrd, idx, &xs);
if (ret < 0)
goto xfer_exit;

@@ -1433,7 +1463,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
/* Hook the request */
thrd->lstenq = idx;
thrd->req[idx].desc = desc;
- _setup_req(0, thrd, idx, &xs);
+ _setup_req(pl330, 0, thrd, idx, &xs);

ret = 0;

@@ -2557,7 +2587,7 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(

desc->rqtype = direction;
desc->rqcfg.brst_size = pch->burst_sz;
- desc->rqcfg.brst_len = 1;
+ desc->rqcfg.brst_len = pch->burst_len;
desc->bytes_requested = period_len;
fill_px(&desc->px, dst, src, period_len);

@@ -2702,7 +2732,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
}

desc->rqcfg.brst_size = pch->burst_sz;
- desc->rqcfg.brst_len = 1;
+ desc->rqcfg.brst_len = pch->burst_len;
desc->rqtype = direction;
desc->bytes_requested = sg_dma_len(sg);
}
@@ -2778,6 +2808,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
struct resource *res;
int i, ret, irq;
int num_chan;
+ struct device_node *np = adev->dev.of_node;

pdat = dev_get_platdata(&adev->dev);

@@ -2797,6 +2828,11 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)

pl330->mcbufsz = pdat ? pdat->mcbuf_sz : 0;

+ /* get quirk */
+ for (i = 0; i < ARRAY_SIZE(of_quirks); i++)
+ if (of_property_read_bool(np, of_quirks[i].quirk))
+ pl330->quirks |= of_quirks[i].id;
+
res = &adev->res;
pl330->base = devm_ioremap_resource(&adev->dev, res);
if (IS_ERR(pl330->base))
diff --git a/arch/arm/boot/dts/rk3xxx.dtsi b/arch/arm/boot/dts/rk3xxx.dtsi
index a2ae9f3..fb5b4ec 100644
--- a/arch/arm/boot/dts/rk3xxx.dtsi
+++ b/arch/arm/boot/dts/rk3xxx.dtsi
@@ -94,6 +94,7 @@

dmac2: dma-controller@20078000 {
compatible = "arm,pl330", "arm,primecell";
+ broken-no-flushp;
reg = <0x20078000 0x4000>;
interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;