On Fri, Jan 07, 2011 at 07:56:34PM +0530, Santosh Shilimkar wrote: > > -----Original Message----- > > From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxxx] > > Sent: Friday, January 07, 2011 7:55 PM > > To: Santosh Shilimkar > > Cc: linux-omap@xxxxxxxxxxxxxxx; Tony Lindgren > > Subject: Re: 4430SDP boot failure > > > > On Fri, Jan 07, 2011 at 06:39:06PM +0530, Santosh Shilimkar wrote: > > > Have sent you latest bootloaders and full bootlog on my ES1.0 > > > OMAP4430SDP. 2.6.37 just boots fine for me. > > > > > > Low level debug as you reported seems to be broken though. > > > > Many thanks, the new mlo and uboot gets dhcp/tftp working nicely on > > the board - which should ease the debugging problem as it no longer > > requires anything but the reset button pressed to test a new kernel. > > Glad to hear that. And, with one ARM errata disabled, the kernel finally boots. So the "X-Loader hangs" message means that we did something that non-secure mode prevented us from doing. It would be a good idea if X-loader could tell dump out the exception, register dump, and for data/prefetch aborts, the relevent FSR and FAR registers - that would make debugging this kind of failure a lot easier. ================= Subject: Fix DMA API usage in OMAP MCSPI driver Running the latest kernel on the 4430SDP board with DMA API debugging enabled results in this: WARNING: at lib/dma-debug.c:803 check_unmap+0x19c/0x6f0() NULL NULL: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x000000008129901a] [size=260 bytes] Modules linked in: Backtrace: [<c003cbe0>] (dump_backtrace+0x0/0x10c) from [<c0278da8>] (dump_stack+0x18/0x1c) r7:c1839dc0 r6:c0198578 r5:c0304b17 r4:00000323 [<c0278d90>] (dump_stack+0x0/0x1c) from [<c005b158>] (warn_slowpath_common+0x58/0x70) [<c005b100>] (warn_slowpath_common+0x0/0x70) from [<c005b214>] (warn_slowpath_fmt+0x38/0x40) r8:c1839e40 r7:00000000 r6:00000104 r5:00000000 r4:8129901a [<c005b1dc>] (warn_slowpath_fmt+0x0/0x40) from [<c0198578>] (check_unmap+0x19c/0x6f0) r3:c03110de r2:c0304e6b [<c01983dc>] (check_unmap+0x0/0x6f0) from [<c0198cd8>] (debug_dma_unmap_page+0x74/0x80) [<c0198c64>] (debug_dma_unmap_page+0x0/0x80) from [<c01d5ad8>] (omap2_mcspi_work+0x514/0xbf0) [<c01d55c4>] (omap2_mcspi_work+0x0/0xbf0) from [<c006dfb0>] (process_one_work+0x294/0x400) [<c006dd1c>] (process_one_work+0x0/0x400) from [<c006e50c>] (worker_thread+0x220/0x3f8) [<c006e2ec>] (worker_thread+0x0/0x3f8) from [<c00738d0>] (kthread+0x88/0x90) [<c0073848>] (kthread+0x0/0x90) from [<c005e924>] (do_exit+0x0/0x5fc) r7:00000013 r6:c005e924 r5:c0073848 r4:c1829ee0 ---[ end trace 1b75b31a2719ed20 ]--- I've no idea why this driver uses NULL for dma_unmap_single instead of the &spi->dev that is laying around just waiting to be used in that function - but it's an easy fix. Also replace this comment with a FIXME comment: /* Do DMA mapping "early" for better error reporting and * dcache use. Note that if dma_unmap_single() ever starts * to do real work on ARM, we'd need to clean up mappings * for previous transfers on *ALL* exits of this loop... */ as the comment is not true - we do work in dma_unmap() functions, particularly on ARMv6 and above. I've corrected the existing unmap functions but if any others are required they must be added ASAP. Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> --- I'm surprised this driver got merged as it has such a comment, and is abusing the DMA API... well, at least with the DMA API debugging we can now catch this stuff. diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index 951a160..abb1ffb 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -397,7 +397,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) if (tx != NULL) { wait_for_completion(&mcspi_dma->dma_tx_completion); - dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE); + dma_unmap_single(&spi->dev, xfer->tx_dma, count, DMA_TO_DEVICE); /* for TX_ONLY mode, be sure all words have shifted out */ if (rx == NULL) { @@ -412,7 +412,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) if (rx != NULL) { wait_for_completion(&mcspi_dma->dma_rx_completion); - dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE); + dma_unmap_single(&spi->dev, xfer->rx_dma, count, DMA_FROM_DEVICE); omap2_mcspi_set_enable(spi, 0); if (l & OMAP2_MCSPI_CHCONF_TURBO) { @@ -1025,11 +1025,6 @@ static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m) if (m->is_dma_mapped || len < DMA_MIN_BYTES) continue; - /* Do DMA mapping "early" for better error reporting and - * dcache use. Note that if dma_unmap_single() ever starts - * to do real work on ARM, we'd need to clean up mappings - * for previous transfers on *ALL* exits of this loop... - */ if (tx_buf != NULL) { t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf, len, DMA_TO_DEVICE); @@ -1046,7 +1041,7 @@ static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m) dev_dbg(&spi->dev, "dma %cX %d bytes error\n", 'R', len); if (tx_buf != NULL) - dma_unmap_single(NULL, t->tx_dma, + dma_unmap_single(&spi->dev, t->tx_dma, len, DMA_TO_DEVICE); return -EINVAL; } -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
