From daf5822f05397623c6d2376748c7965707cf8ef8 Mon Sep 17 00:00:00 2001 From: Sonic Zhang <sonic.zhang@analog.com> Date: Mon, 16 Nov 2009 19:13:08 +0530 Subject: [PATCH] USB: musb: add notes for Blackfin anomalies Add some helpful notes about how the driver works around different anomalies that exist in the on-chip host controller. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Cliff Cai <cliff.cai@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Anand Gadiyar <gadiyar@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- drivers/usb/musb/blackfin.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/usb/musb/blackfin.h b/drivers/usb/musb/blackfin.h index a240c1e53d16e..b49a362fb9faa 100644 --- a/drivers/usb/musb/blackfin.h +++ b/drivers/usb/musb/blackfin.h @@ -14,6 +14,33 @@ * Blackfin specific definitions */ +/* Anomalies notes: + * + * 05000450 - USB DMA Mode 1 Short Packet Data Corruption: + * MUSB driver is designed to transfer buffer of N * maxpacket size + * in DMA mode 1 and leave the rest of the data to the next + * transfer in DMA mode 0, so we never transmit a short packet in + * DMA mode 1. + * + * 05000463 - This anomaly doesn't affect this driver since it + * never uses L1 or L2 memory as data destination. + * + * 05000464 - This anomaly doesn't affect this driver since it + * never uses L1 or L2 memory as data source. + * + * 05000465 - The anomaly can be seen when SCLK is over 100 MHz, and there is + * no way to workaround for bulk endpoints. Since the wMaxPackSize + * of bulk is less than or equal to 512, while the fifo size of + * endpoint 5, 6, 7 is 1024, the double buffer mode is enabled + * automatically when these endpoints are used for bulk OUT. + * + * 05000466 - This anomaly doesn't affect this driver since it never mixes + * concurrent DMA and core accesses to the TX endpoint FIFOs. + * + * 05000467 - The workaround for this anomaly will introduce another + * anomaly - 05000465. + */ + #undef DUMP_FIFO_DATA #ifdef DUMP_FIFO_DATA static void dump_fifo_data(u8 *buf, u16 len) -- GitLab