On Thu, Mar 28, 2013 at 03:44:50PM +0200, Ruslan Bilovol wrote: > Hi Felipe, > > On Wed, Mar 27, 2013 at 3:17 PM, Felipe Balbi <balbi@xxxxxx> wrote: > > Hi, > > > > On Thu, Mar 14, 2013 at 08:12:09PM +0200, Ruslan Bilovol wrote: > >> MUSB controller cannot work in DMA mode with misaligned buffers, > >> switching in PIO mode. > >> > >> HCD core has hooks that allow to override the default DMA > >> mapping and unmapping routines for host controllers that have > >> special DMA requirements, such as alignment contraints. > >> > >> It is observed that work in PIO mode is slow and it's better > >> to align buffers properly before passing them to MUSB > >> > >> This increased throughput 80->120 MBits/s over musb@omap4 with > >> USB Gigabit ethernet adapter attached. > >> > >> Some ideas taken from ehci-tegra.c > >> > >> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxx> > >> --- > >> drivers/usb/musb/musb_core.c | 14 ++++++ > >> drivers/usb/musb/musb_host.c | 102 +++++++++++++++++++++++++++++++++++++++++- > >> drivers/usb/musb/musb_host.h | 2 +- > >> 3 files changed, 116 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > >> index 60b41cc..91ac166 100644 > >> --- a/drivers/usb/musb/musb_core.c > >> +++ b/drivers/usb/musb/musb_core.c > >> @@ -1431,6 +1431,20 @@ static int musb_core_init(u16 musb_type, struct musb *musb) > >> > >> /* log release info */ > >> musb->hwvers = musb_read_hwvers(mbase); > >> + > >> +#ifndef CONFIG_MUSB_PIO_ONLY > >> + /* > >> + * The DMA engine in RTL1.8 and above cannot handle > >> + * DMA addresses that are not aligned to a 4 byte boundary. > >> + * For such engine implemented (un)map_urb_for_dma hooks. > >> + * Do not use these hooks for RTL<1.8 > >> + */ > >> + if (musb->hwvers < MUSB_HWVERS_1800) { > > > > if you move this check to map/unmap and always return error if this is > > true, you can avoid removing 'const' from our struct hc_driver. Would > > that work ? > > If we return an error in map/unmap callbacks, this will break urb transferring, > however I can call core function usb_hcd_(un)map_urb_for_dma() instead of > returning the error (and that is default behavior if we do not have > map/unmap callbacks > set for the hc driver) so I can avoid removing 'const' from our struct > hc_driver and this will work. > The side effect will be only in small overhead for this path. > > So, will be this OK for you? I will send v3 in this case. should be alright. Thanks -- balbi
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