On Thu, Jul 28, 2011 at 9:45 PM, Felipe Balbi <balbi@xxxxxx> wrote:
> Hi,
>
> On Tue, Jul 19, 2011 at 10:11:58PM -0700, Vikram Pandita wrote:
>> From: Anand Gadiyar <gadiyar@xxxxxx>
>>
>> This patch enables the DMA mode1 RX support.
>> This feature is enabled based on the short_not_ok flag passed from
>> gadget drivers.
>>
>> This will result in a thruput performance gain of around
>> 40% for USB mass-storage/mtp use cases.
>>
>> Signed-off-by: Anand Gadiyar <gadiyar@xxxxxx>
>> Signed-off-by: Moiz Sonasath <m-sonasath@xxxxxx>
>> Signed-off-by: Vikram Pandita <vikram.pandita@xxxxxx>
>> Tested-by: Vikram Pandita <vikram.pandita@xxxxxx>
>
> applied this one, but I changed commit log and code comment a little
> bit. Here's updated commit:
>
> commit e9c281b174f188adb7950ea8f6a55ca07be69914
> Author: Anand Gadiyar <gadiyar@xxxxxx>
> Date: Tue Jul 19 22:11:58 2011 -0700
>
> usb: musb: Enable DMA mode1 RX for transfers without short packets
>
> This patch enables DMA mode1 for the RX patch when we know
> there won't be any short packets. We check that by looking
> into the short_no_ok flag, if it's true we enable mode1, otherwise
> we use mode0 to transfer the data.
>
> This will result in a throughput performance gain of around
> 40% for USB mass-storage/mtp use cases.
>
> [ balbi@xxxxxx : updated commit log and code comments slightly ]
Ack
>
> Signed-off-by: Anand Gadiyar <gadiyar@xxxxxx>
> Signed-off-by: Moiz Sonasath <m-sonasath@xxxxxx>
> Signed-off-by: Vikram Pandita <vikram.pandita@xxxxxx>
> Tested-by: Vikram Pandita <vikram.pandita@xxxxxx>
> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
>
> diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> index b67a062..d314f58 100644
> --- a/drivers/usb/musb/musb_gadget.c
> +++ b/drivers/usb/musb/musb_gadget.c
> @@ -634,6 +634,7 @@ static void rxstate(struct musb *musb, struct musb_request *req)
> u16 len;
> u16 csr = musb_readw(epio, MUSB_RXCSR);
> struct musb_hw_ep *hw_ep = &musb->endpoints[epnum];
> + u8 use_mode_1;
>
> if (hw_ep->is_shared_fifo)
> musb_ep = &hw_ep->ep_in;
> @@ -683,6 +684,18 @@ static void rxstate(struct musb *musb, struct musb_request *req)
>
> if (csr & MUSB_RXCSR_RXPKTRDY) {
> len = musb_readw(epio, MUSB_RXCOUNT);
> +
> + /*
> + * Enable Mode 1 on RX transfers only when short_not_ok flag
> + * is set. Currently short_not_ok flag is set only from
> + * file_storage and f_mass_storage drivers
> + */
> +
> + if (request->short_not_ok && len == musb_ep->packet_sz)
> + use_mode_1 = 1;
> + else
> + use_mode_1 = 0;
> +
> if (request->actual < request->length) {
> #ifdef CONFIG_USB_INVENTRA_DMA
> if (is_buffer_mapped(req)) {
> @@ -714,37 +727,41 @@ static void rxstate(struct musb *musb, struct musb_request *req)
> * then becomes usable as a runtime "use mode 1" hint...
> */
>
> - csr |= MUSB_RXCSR_DMAENAB;
> -#ifdef USE_MODE1
> - csr |= MUSB_RXCSR_AUTOCLEAR;
> - /* csr |= MUSB_RXCSR_DMAMODE; */
> -
> - /* this special sequence (enabling and then
> - * disabling MUSB_RXCSR_DMAMODE) is required
> - * to get DMAReq to activate
> - */
> - musb_writew(epio, MUSB_RXCSR,
> - csr | MUSB_RXCSR_DMAMODE);
> -#else
> - if (!musb_ep->hb_mult &&
> - musb_ep->hw_ep->rx_double_buffered)
> + /* Experimental: Mode1 works with mass storage use cases */
> + if (use_mode_1) {
> csr |= MUSB_RXCSR_AUTOCLEAR;
> -#endif
> - musb_writew(epio, MUSB_RXCSR, csr);
> + musb_writew(epio, MUSB_RXCSR, csr);
> + csr |= MUSB_RXCSR_DMAENAB;
> + musb_writew(epio, MUSB_RXCSR, csr);
> +
> + /*
> + * this special sequence (enabling and then
> + * disabling MUSB_RXCSR_DMAMODE) is required
> + * to get DMAReq to activate
> + */
> + musb_writew(epio, MUSB_RXCSR,
> + csr | MUSB_RXCSR_DMAMODE);
> + musb_writew(epio, MUSB_RXCSR, csr);
> +
> + } else {
> + if (!musb_ep->hb_mult &&
> + musb_ep->hw_ep->rx_double_buffered)
> + csr |= MUSB_RXCSR_AUTOCLEAR;
> + csr |= MUSB_RXCSR_DMAENAB;
> + musb_writew(epio, MUSB_RXCSR, csr);
> + }
>
> if (request->actual < request->length) {
> int transfer_size = 0;
> -#ifdef USE_MODE1
> - transfer_size = min(request->length - request->actual,
> - channel->max_len);
> -#else
> - transfer_size = min(request->length - request->actual,
> - (unsigned)len);
> -#endif
> - if (transfer_size <= musb_ep->packet_sz)
> - musb_ep->dma->desired_mode = 0;
> - else
> + if (use_mode_1) {
> + transfer_size = min(request->length - request->actual,
> + channel->max_len);
> musb_ep->dma->desired_mode = 1;
> + } else {
> + transfer_size = min(request->length - request->actual,
> + (unsigned)len);
> + musb_ep->dma->desired_mode = 0;
> + }
>
> use_dma = c->channel_program(
> channel,
>
> --
> balbi
>
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