On 1/14/19 6:30 AM, Vignesh R wrote:
On 14/01/19 2:19 AM, David Lechner wrote:
This reverts commit b682cffa3ac6d9d9e16e9b413c45caee3b391fab.
That commit breaks displays using tinydrm drivers, such as ili9225.
It causes corruption in the image that is displayed (it looks like only
1/2 of the framebuffer data is sent, the other half of the display
remains blank.)
The following error appears multiple times:
ili9225 spi1.0: EOW timed out
Eventually, the system locks up without any additional errors.
Oops, that's unfortunate. I see ili9225 is using bits_per_word = 16.
I believe commit b682cffa3ac6d9d broke spi_transfers where
bits_per_word anything other than 8 bits.
I don't have ili9225 HW but was able emulate this condition using a SPI
flash as slave on AM335x and successfully reproduced the issue. Could
you test if this diff[1] helps in fixing the regression without needing
to revert commit b682cffa3ac6d9d?
If below diff does not help, then could you post logs of types of
spi_transfers being queued by ili9225 driver? I guess you can dump them
by enabling DEBUG option in tinydrm-helpers.c.
Also which TI SoC are you using?
Sorry for the trouble!
[1]:
Adjust maxburst size of DMA xfer according to the DMA trigger level and word length
instead of just word length
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 2fd8881fcd65..6b7edcff0e6b 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -623,8 +623,8 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
cfg.src_addr_width = width;
cfg.dst_addr_width = width;
- cfg.src_maxburst = es;
- cfg.dst_maxburst = es;
+ cfg.src_maxburst = width / es;
+ cfg.dst_maxburst = width / es;
Just an observation... won't `width / es` always == 1 because width is always == es?
rx = xfer->rx_buf;
tx = xfer->tx_buf;
