Re: [PATCH v10 05/12] dmaengine: dma: imx-sdma: add fw_loaded and is_ram_script
From: Frieder Schrempf
Date: Thu Jul 23 2020 - 07:51:55 EST
On 23.07.20 13:12, Robin Gong wrote:
On 2020/07/23 17:04 Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
wrote:
Hi Robin,
On 30.06.20 15:31, Robin Gong wrote:
Add 'fw_loaded' and 'is_ram_script' to check if the script used by
channel is ram script and it's loaded or not, so that could prevent
meaningless following malloc dma descriptor and bd allocate in
sdma_transfer_init(), otherwise memory may be consumed out
potentially without free in case that spi fallback into pio while
dma transfer failed by sdma firmware not ready(next ERR009165 patch
depends on sdma
RAM scripts/firmware).
Signed-off-by: Robin Gong <yibin.gong@xxxxxxx>
Acked-By: Vinod Koul <vkoul@xxxxxxxxxx>
---
drivers/dma/imx-sdma.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index
5411e01e..ce1c83e 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -379,6 +379,7 @@ struct sdma_channel {
enum dma_status status;
struct imx_dma_data data;
struct work_struct terminate_worker;
+ bool is_ram_script;
};
#define IMX_DMA_SG_LOOP BIT(0)
@@ -443,6 +444,7 @@ struct sdma_engine {
struct sdma_buffer_descriptor *bd0;
/* clock ratio for AHB:SDMA core. 1:1 is 1, 2:1 is 0*/
bool clk_ratio;
+ bool fw_loaded;
};
static int sdma_config_write(struct dma_chan *chan, @@ -929,6
+931,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,
case IMX_DMATYPE_SSI_DUAL:
per_2_emi = sdma->script_addrs->ssish_2_mcu_addr;
emi_2_per = sdma->script_addrs->mcu_2_ssish_addr;
+ sdmac->is_ram_script = true;
break;
case IMX_DMATYPE_SSI_SP:
case IMX_DMATYPE_MMC:
@@ -943,6 +946,7 @@ static void sdma_get_pc(struct sdma_channel
*sdmac,
per_2_emi = sdma->script_addrs->asrc_2_mcu_addr;
emi_2_per = sdma->script_addrs->asrc_2_mcu_addr;
per_2_per = sdma->script_addrs->per_2_per_addr;
+ sdmac->is_ram_script = true;
break;
case IMX_DMATYPE_ASRC_SP:
per_2_emi = sdma->script_addrs->shp_2_mcu_addr;
@@ -1339,6 +1343,11 @@ static struct sdma_desc
*sdma_transfer_init(struct sdma_channel *sdmac,
{
struct sdma_desc *desc;
+ if (!sdmac->sdma->fw_loaded && sdmac->is_ram_script) {
+ dev_err(sdmac->sdma->dev, "sdma firmware not ready!\n");
+ goto err_out;
+ }
I tried your v10 patches on next-20200722 with i.MX8MM and it mostly
seems to work fine.
When I tried first, I had the imx-sdma driver compiled into the
kernel, so it didn't load the firmware and fell back to the ROM scripts.
With this, SPI transactions work just fine, but I got the above error
message printed continuously when sending data in SPI3 via spidev.
That's caused by you didn't load ram firmware as this patch set described.
Please follow below steps to load firmware manually if you don't want to use
NXP official Yocto release package:
1. Get sdma firmware from below linux-firmware and copy it to your local
rootfs /lib/firmware/imx/sdma.
https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ffirmware%2Flinux-firmware.git%2Ft&data=02%7C01%7Cfrieder.schrempf%40kontron.de%7C08276b76f9a14dae1f8408d82ef94da1%7C8c9d3c973fd941c8a2b1646f3942daf1%7C0%7C0%7C637310995564511410&sdata=YA1455ILoNgRDHAOy1H2051J9cu5VsHk39xtQive8mo%3D&reserved=0
ree/imx/sdma
2. Load firmware manually:
echo 1 > /sys/$DEVPATH/loading
cat $MY_FW_DIR/$FIRMWARE > /sys/$DEVPATH/data
echo 0 > /sys/$DEVPATH/loading
Please refer to Documentation/driver-api/firmware/fallback-mechanisms.rst
and load the firmware in 60s (firmware fallback loading timeout) from kernel
boot up.
When I build imx-sdma as a module, the firmware is loaded correctly
and everything works as expected.
I guess that's not related with sdma building as module. If sdma build as
module, spi will fall to pio mode at spi-imx driver probe phase so that the
above warning log never to be walked. Would you please add some debug
info to double confirm?
Hi Frider,
Please ignore this comment, since there is -EPROBE_DEFER checking
, so you load sdma firmware by building sdma driver as module instead of
the above comment I mentioned?
Yes, correct.
The warning log comes out during spi
transfer start and sdma firmware loading done, but if sdma driver building as
module could ensure firmware loading done in sdma_driver_probe_phase->
spi_imx_probe_phase, which means sdma firmware loading has been ready
before spi transfer start, hence no such warning message.
But I am not sure if all client drivers except spi are in good shape to support
' CONFIG_IMX_SDMA=m '.
I'm pretty sure that CONFIG_IMX_SDMA=m is supported and common.
Otherwise it wouldn't be an option in Kconfig.
Besides, do you think 'dev_err_once ' instead of 'dev_err' is okay for you?
I can't really judge if this is a proper fix as I haven't looked at the
code in detail, but if you want to use dev_err_once(), that would be ok
for me, maybe even better dev_warn_once().
As chances are that even without firmware transfers will work a warning
instead of an error makes more sense to me.