USB controller may access a wrong address for the dTD (endpoint transfer descriptor) and then hang. This happens a lot when doing tests with g_ether module and iperf, a tool for measuring maximum TCP and UDP bandwidth. This hardware bug is explained in detail by errata number 2858 for i.MX23: http://cache.freescale.com/files/dsp/doc/errata/IMX23CE.pdf All (?) SOCs with an IP from chipidea suffer from this problem. mv_udc_core fixes this bug by commit daec765. There still may be unfixed drivers. Signed-off-by: Christoph Fritz <chf.fritz@xxxxxxxxxxxxxx> Signed-off-by: Christian Hemp <c.hemp@xxxxxxxxx> Reviewed-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> --- drivers/usb/gadget/fsl_udc_core.c | 12 +++++++++++- drivers/usb/gadget/fsl_usb2_udc.h | 2 ++ 2 files changed, 13 insertions(+), 1 deletions(-) diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c index 53df9c0..deaab62 100644 --- a/drivers/usb/gadget/fsl_udc_core.c +++ b/drivers/usb/gadget/fsl_udc_core.c @@ -88,8 +88,13 @@ static void done(struct fsl_ep *ep, struct fsl_req *req, int status) curr_td = next_td; if (j != req->dtd_count - 1) { next_td = curr_td->next_td_virt; + dma_pool_free(udc->td_pool, curr_td, curr_td->td_dma); + } else { + if (udc->last_free_td != NULL) + dma_pool_free(udc->td_pool, udc->last_free_td, + udc->last_free_td->td_dma); + udc->last_free_td = curr_td; } - dma_pool_free(udc->td_pool, curr_td, curr_td->td_dma); } if (req->mapped) { @@ -2439,6 +2444,7 @@ static int __init fsl_udc_probe(struct platform_device *pdev) udc->gadget.speed = USB_SPEED_UNKNOWN; udc->gadget.name = driver_name; udc->vbus_active = true; + udc->last_free_td = NULL; /* Setup gadget.dev and register with kernel */ dev_set_name(&udc->gadget.dev, "gadget"); @@ -2533,6 +2539,10 @@ static int __exit fsl_udc_remove(struct platform_device *pdev) kfree(udc->status_req); kfree(udc->eps); + if (udc->last_free_td != NULL) + dma_pool_free(udc->td_pool, udc->last_free_td, + udc->last_free_td->td_dma); + dma_pool_destroy(udc->td_pool); free_irq(udc->irq, udc); iounmap(dr_regs); diff --git a/drivers/usb/gadget/fsl_usb2_udc.h b/drivers/usb/gadget/fsl_usb2_udc.h index f61a967..a0123ae 100644 --- a/drivers/usb/gadget/fsl_usb2_udc.h +++ b/drivers/usb/gadget/fsl_usb2_udc.h @@ -497,6 +497,8 @@ struct fsl_udc { size_t ep_qh_size; /* size after alignment adjustment*/ dma_addr_t ep_qh_dma; /* dma address of QH */ + struct ep_td_struct *last_free_td; + u32 max_pipes; /* Device max pipes */ u32 bus_reset; /* Device is bus resetting */ u32 resume_state; /* USB state to resume */ -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
