Hi Peter,
>
> On 21-03-09 06:19:39, Sanket Parmar wrote:
> > Allocation of DMA coherent memory in atomic context using
> > dma_alloc_coherent() might fail on platforms with smaller
> > DMA region.
> >
> > To fix it, dma_alloc_coherent() is replaced with dma_pool
> > API to allocate a smaller chunk of DMA coherent memory for
> > TRB rings.
> >
> > Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
>
> The patch is ok, but I don't think it is a bug-fix, it is an
> improvement for smaller DMA region use case.
>
> I will apply it with deletion of above Fixes tag if you have no
> more opinion.
>
Please go ahead.
Thanks,
Sanket
> Peter
> > Reported-by: Aswath Govindraju <[email protected]>
> > Signed-off-by: Sanket Parmar <[email protected]>
> > ---
> > drivers/usb/cdns3/cdns3-gadget.c | 42 +++++++++++++++++---------------
> -----
> > drivers/usb/cdns3/cdns3-gadget.h | 1 +
> > 2 files changed, 20 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-
> gadget.c
> > index 582bfec..5f51215 100644
> > --- a/drivers/usb/cdns3/cdns3-gadget.c
> > +++ b/drivers/usb/cdns3/cdns3-gadget.c
> > @@ -59,6 +59,7 @@
> > #include <linux/dma-mapping.h>
> > #include <linux/usb/gadget.h>
> > #include <linux/module.h>
> > +#include <linux/dmapool.h>
> > #include <linux/iopoll.h>
> >
> > #include "core.h"
> > @@ -190,29 +191,13 @@ dma_addr_t cdns3_trb_virt_to_dma(struct
> cdns3_endpoint *priv_ep,
> > return priv_ep->trb_pool_dma + offset;
> > }
> >
> > -static int cdns3_ring_size(struct cdns3_endpoint *priv_ep)
> > -{
> > - switch (priv_ep->type) {
> > - case USB_ENDPOINT_XFER_ISOC:
> > - return TRB_ISO_RING_SIZE;
> > - case USB_ENDPOINT_XFER_CONTROL:
> > - return TRB_CTRL_RING_SIZE;
> > - default:
> > - if (priv_ep->use_streams)
> > - return TRB_STREAM_RING_SIZE;
> > - else
> > - return TRB_RING_SIZE;
> > - }
> > -}
> > -
> > static void cdns3_free_trb_pool(struct cdns3_endpoint *priv_ep)
> > {
> > struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
> >
> > if (priv_ep->trb_pool) {
> > - dma_free_coherent(priv_dev->sysdev,
> > - cdns3_ring_size(priv_ep),
> > - priv_ep->trb_pool, priv_ep-
> >trb_pool_dma);
> > + dma_pool_free(priv_dev->eps_dma_pool,
> > + priv_ep->trb_pool, priv_ep->trb_pool_dma);
> > priv_ep->trb_pool = NULL;
> > }
> > }
> > @@ -226,7 +211,7 @@ static void cdns3_free_trb_pool(struct
> cdns3_endpoint *priv_ep)
> > int cdns3_allocate_trb_pool(struct cdns3_endpoint *priv_ep)
> > {
> > struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
> > - int ring_size = cdns3_ring_size(priv_ep);
> > + int ring_size = TRB_RING_SIZE;
> > int num_trbs = ring_size / TRB_SIZE;
> > struct cdns3_trb *link_trb;
> >
> > @@ -234,10 +219,10 @@ int cdns3_allocate_trb_pool(struct
> cdns3_endpoint *priv_ep)
> > cdns3_free_trb_pool(priv_ep);
> >
> > if (!priv_ep->trb_pool) {
> > - priv_ep->trb_pool = dma_alloc_coherent(priv_dev->sysdev,
> > - ring_size,
> > - &priv_ep-
> >trb_pool_dma,
> > - GFP_DMA32 |
> GFP_ATOMIC);
> > + priv_ep->trb_pool = dma_pool_alloc(priv_dev-
> >eps_dma_pool,
> > + GFP_DMA32 |
> GFP_ATOMIC,
> > + &priv_ep->trb_pool_dma);
> > +
> > if (!priv_ep->trb_pool)
> > return -ENOMEM;
> >
> > @@ -3113,6 +3098,7 @@ static void cdns3_gadget_exit(struct cdns *cdns)
> >
> > dma_free_coherent(priv_dev->sysdev, 8, priv_dev->setup_buf,
> > priv_dev->setup_dma);
> > + dma_pool_destroy(priv_dev->eps_dma_pool);
> >
> > kfree(priv_dev->zlp_buf);
> > usb_put_gadget(&priv_dev->gadget);
> > @@ -3185,6 +3171,14 @@ static int cdns3_gadget_start(struct cdns *cdns)
> > /* initialize endpoint container */
> > INIT_LIST_HEAD(&priv_dev->gadget.ep_list);
> > INIT_LIST_HEAD(&priv_dev->aligned_buf_list);
> > + priv_dev->eps_dma_pool =
> dma_pool_create("cdns3_eps_dma_pool",
> > + priv_dev->sysdev,
> > + TRB_RING_SIZE, 8, 0);
> > + if (!priv_dev->eps_dma_pool) {
> > + dev_err(priv_dev->dev, "Failed to create TRB dma pool\n");
> > + ret = -ENOMEM;
> > + goto err1;
> > + }
> >
> > ret = cdns3_init_eps(priv_dev);
> > if (ret) {
> > @@ -3235,6 +3229,8 @@ static int cdns3_gadget_start(struct cdns *cdns)
> > err2:
> > cdns3_free_all_eps(priv_dev);
> > err1:
> > + dma_pool_destroy(priv_dev->eps_dma_pool);
> > +
> > usb_put_gadget(&priv_dev->gadget);
> > cdns->gadget_dev = NULL;
> > return ret;
> > diff --git a/drivers/usb/cdns3/cdns3-gadget.h b/drivers/usb/cdns3/cdns3-
> gadget.h
> > index 21fa461..ecf9b91 100644
> > --- a/drivers/usb/cdns3/cdns3-gadget.h
> > +++ b/drivers/usb/cdns3/cdns3-gadget.h
> > @@ -1298,6 +1298,7 @@ struct cdns3_device {
> >
> > struct cdns3_usb_regs __iomem *regs;
> >
> > + struct dma_pool *eps_dma_pool;
> > struct usb_ctrlrequest *setup_buf;
> > dma_addr_t setup_dma;
> > void *zlp_buf;
> > --
> > 1.7.1
> >
>
> --
>
> Thanks,
> Peter Chen
