Hi Mathias, I have tested this patch with my platform and it works fine
Thanks, Anurag Kumar Vulisha >-----Original Message----- >From: Mathias Nyman [mailto:mathias.ny...@linux.intel.com] >Sent: Friday, June 02, 2017 4:51 PM >To: Anurag Kumar Vulisha <anura...@xilinx.com> >Cc: gre...@linuxfoundation.org; Anirudha Sarangi <anir...@xilinx.com>; >Anurag Kumar Vulisha <anura...@xilinx.com>; linux-usb@vger.kernel.org; >Mathias Nyman <mathias.ny...@linux.intel.com> >Subject: [PATCH] xhci: remove endpoint ring cache > >Having a properly working ring cache could ease a bit the memory >reallocation, but this current implemetation isn't the correct way. >It's faulty and hogs a lot of memory. > >A pool of cached rings that any device could use would be more useful, >but xhci driver isn't there yet, just keeping the basic functionality >working is already a handful. > >How about your case, does removing the cache work instead with your setup? > >8<------- > >Anurag Kumar Vulisha reported several issues with xhci endpoint >ring caching. > >31 Rings are cached per device before a ring is freed. >These cached rings are not used as default if a new ring is needed. >They are only used if the drive fails to allocate memory for a ring. > >The current ring cache is more a reason to why we run out memry than a >help when we actually do so. > >Anurag Kumar Vulisha tried to use cached rings as a first option and >found new issues with cached ring initialization. >Cached rings were first zeroed and then manually reinitialized with link >rbs etc, but forgetting to set some important bits like cycle toggle bit. > >Remove the ring cache completely as it's a faulty premature optimization >eating memory > >Reported-by: Anurag Kumar Vulisha <anura...@xilinx.com> >Signed-off-by: Mathias Nyman <mathias.ny...@linux.intel.com> >--- > drivers/usb/host/xhci-mem.c | 81 ++++----------------------------------------- > drivers/usb/host/xhci.c | 17 +++++----- > drivers/usb/host/xhci.h | 6 +--- > 3 files changed, 15 insertions(+), 89 deletions(-) > >diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c >index 1f1687e..7c2501a 100644 >--- a/drivers/usb/host/xhci-mem.c >+++ b/drivers/usb/host/xhci-mem.c >@@ -407,64 +407,17 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd >*xhci, > return NULL; > } > >-void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci, >+void xhci_free_endpoint_ring(struct xhci_hcd *xhci, > struct xhci_virt_device *virt_dev, > unsigned int ep_index) > { >- int rings_cached; >- >- rings_cached = virt_dev->num_rings_cached; >- if (rings_cached < XHCI_MAX_RINGS_CACHED) { >- virt_dev->ring_cache[rings_cached] = >- virt_dev->eps[ep_index].ring; >- virt_dev->num_rings_cached++; >- xhci_dbg(xhci, "Cached old ring, " >- "%d ring%s cached\n", >- virt_dev->num_rings_cached, >- (virt_dev->num_rings_cached > 1) ? "s" : ""); >- } else { >- xhci_ring_free(xhci, virt_dev->eps[ep_index].ring); >- xhci_dbg(xhci, "Ring cache full (%d rings), " >- "freeing ring\n", >- virt_dev->num_rings_cached); >- } >+ xhci_ring_free(xhci, virt_dev->eps[ep_index].ring); > virt_dev->eps[ep_index].ring = NULL; > } > >-/* Zero an endpoint ring (except for link TRBs) and move the enqueue and >dequeue >- * pointers to the beginning of the ring. >- */ >-static void xhci_reinit_cached_ring(struct xhci_hcd *xhci, >- struct xhci_ring *ring, unsigned int cycle_state, >- enum xhci_ring_type type) >-{ >- struct xhci_segment *seg = ring->first_seg; >- int i; >- >- do { >- memset(seg->trbs, 0, >- sizeof(union xhci_trb)*TRBS_PER_SEGMENT); >- if (cycle_state == 0) { >- for (i = 0; i < TRBS_PER_SEGMENT; i++) >- seg->trbs[i].link.control |= >- cpu_to_le32(TRB_CYCLE); >- } >- /* All endpoint rings have link TRBs */ >- xhci_link_segments(xhci, seg, seg->next, type); >- seg = seg->next; >- } while (seg != ring->first_seg); >- ring->type = type; >- xhci_initialize_ring_info(ring, cycle_state); >- /* td list should be empty since all URBs have been cancelled, >- * but just in case... >- */ >- INIT_LIST_HEAD(&ring->td_list); >-} >- > /* > * Expand an existing ring. >- * Look for a cached ring or allocate a new ring which has same segment >numbers >- * and link the two rings. >+ * Allocate a new ring which has same segment numbers and link the two rings. > */ > int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring, > unsigned int num_trbs, gfp_t flags) >@@ -968,12 +921,6 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int >slot_id) > /* If necessary, update the number of active TTs on this root port */ > xhci_update_tt_active_eps(xhci, dev, old_active_eps); > >- if (dev->ring_cache) { >- for (i = 0; i < dev->num_rings_cached; i++) >- xhci_ring_free(xhci, dev->ring_cache[i]); >- kfree(dev->ring_cache); >- } >- > if (dev->in_ctx) > xhci_free_container_ctx(xhci, dev->in_ctx); > if (dev->out_ctx) >@@ -1062,14 +1009,6 @@ int xhci_alloc_virt_device(struct xhci_hcd *xhci, int >slot_id, > if (!dev->eps[0].ring) > goto fail; > >- /* Allocate pointers to the ring cache */ >- dev->ring_cache = kzalloc( >- sizeof(struct xhci_ring *)*XHCI_MAX_RINGS_CACHED, >- flags); >- if (!dev->ring_cache) >- goto fail; >- dev->num_rings_cached = 0; >- > dev->udev = udev; > > /* Point to output device context in dcbaa. */ >@@ -1537,17 +1476,9 @@ int xhci_endpoint_init(struct xhci_hcd *xhci, > /* Set up the endpoint ring */ > virt_dev->eps[ep_index].new_ring = > xhci_ring_alloc(xhci, 2, 1, ring_type, max_packet, mem_flags); >- if (!virt_dev->eps[ep_index].new_ring) { >- /* Attempt to use the ring cache */ >- if (virt_dev->num_rings_cached == 0) >- return -ENOMEM; >- virt_dev->num_rings_cached--; >- virt_dev->eps[ep_index].new_ring = >- virt_dev->ring_cache[virt_dev->num_rings_cached]; >- virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL; >- xhci_reinit_cached_ring(xhci, virt_dev->eps[ep_index].new_ring, >- 1, ring_type); >- } >+ if (!virt_dev->eps[ep_index].new_ring) >+ return -ENOMEM; >+ > virt_dev->eps[ep_index].skip = false; > ep_ring = virt_dev->eps[ep_index].new_ring; > >diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >index 2d6a98c..ddeb943 100644 >--- a/drivers/usb/host/xhci.c >+++ b/drivers/usb/host/xhci.c >@@ -1695,8 +1695,7 @@ static int xhci_add_endpoint(struct usb_hcd *hcd, >struct usb_device *udev, > if (xhci->quirks & XHCI_MTK_HOST) { > ret = xhci_mtk_add_ep_quirk(hcd, udev, ep); > if (ret < 0) { >- xhci_free_or_cache_endpoint_ring(xhci, >- virt_dev, ep_index); >+ xhci_free_endpoint_ring(xhci, virt_dev, ep_index); > return ret; > } > } >@@ -2720,23 +2719,23 @@ static int xhci_check_bandwidth(struct usb_hcd >*hcd, struct usb_device *udev) > for (i = 1; i < 31; i++) { > if ((le32_to_cpu(ctrl_ctx->drop_flags) & (1 << (i + 1))) && > !(le32_to_cpu(ctrl_ctx->add_flags) & (1 << (i + 1)))) { >- xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i); >+ xhci_free_endpoint_ring(xhci, virt_dev, i); > xhci_check_bw_drop_ep_streams(xhci, virt_dev, i); > } > } > xhci_zero_in_ctx(xhci, virt_dev); > /* > * Install any rings for completely new endpoints or changed endpoints, >- * and free or cache any old rings from changed endpoints. >+ * and free any old rings from changed endpoints. > */ > for (i = 1; i < 31; i++) { > if (!virt_dev->eps[i].new_ring) > continue; >- /* Only cache or free the old ring if it exists. >+ /* Only free the old ring if it exists. > * It may not if this is the first add of an endpoint. > */ > if (virt_dev->eps[i].ring) { >- xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i); >+ xhci_free_endpoint_ring(xhci, virt_dev, i); > } > xhci_check_bw_drop_ep_streams(xhci, virt_dev, i); > virt_dev->eps[i].ring = virt_dev->eps[i].new_ring; >@@ -3336,7 +3335,7 @@ void xhci_free_device_endpoint_resources(struct >xhci_hcd *xhci, > * > * Wait for the Reset Device command to finish. Remove all structures > * associated with the endpoints that were disabled. Clear the input device >- * structure? Cache the rings? Reset the control endpoint 0 max packet size? >+ * structure? Reset the control endpoint 0 max packet size? > * > * If the virt_dev to be reset does not exist or does not match the udev, > * it means the device is lost, possibly due to the xHC restore error and >@@ -3466,7 +3465,7 @@ static int xhci_discover_or_reset_device(struct >usb_hcd *hcd, > spin_unlock_irqrestore(&xhci->lock, flags); > } > >- /* Everything but endpoint 0 is disabled, so free or cache the rings. */ >+ /* Everything but endpoint 0 is disabled, so free the rings. */ > last_freed_endpoint = 1; > for (i = 1; i < 31; i++) { > struct xhci_virt_ep *ep = &virt_dev->eps[i]; >@@ -3480,7 +3479,7 @@ static int xhci_discover_or_reset_device(struct >usb_hcd *hcd, > } > > if (ep->ring) { >- xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i); >+ xhci_free_endpoint_ring(xhci, virt_dev, i); > last_freed_endpoint = i; > } > if (!list_empty(&virt_dev->eps[i].bw_endpoint_list)) >diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h >index 3ef9a8a..acd66f7 100644 >--- a/drivers/usb/host/xhci.h >+++ b/drivers/usb/host/xhci.h >@@ -992,10 +992,6 @@ struct xhci_virt_device { > struct xhci_container_ctx *out_ctx; > /* Used for addressing devices and configuration changes */ > struct xhci_container_ctx *in_ctx; >- /* Rings saved to ensure old alt settings can be re-instated */ >- struct xhci_ring **ring_cache; >- int num_rings_cached; >-#define XHCI_MAX_RINGS_CACHED 31 > struct xhci_virt_ep eps[31]; > u8 fake_port; > u8 real_port; >@@ -1965,7 +1961,7 @@ int xhci_endpoint_init(struct xhci_hcd *xhci, struct >xhci_virt_device *virt_dev, > void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring); > int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring, > unsigned int num_trbs, gfp_t flags); >-void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci, >+void xhci_free_endpoint_ring(struct xhci_hcd *xhci, > struct xhci_virt_device *virt_dev, > unsigned int ep_index); > struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci, >-- >1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
