linux/drivers/bluetooth/btmtkuart.c

1015 lines
24 KiB

Bluetooth: remove duplicate h4_recv_buf() in header The "h4_recv.h" header contains a duplicate h4_recv_buf() that is nearly but not quite identical to the h4_recv_buf() in hci_h4.c. This duplicated header was added in commit 07eb96a5a7b0 ("Bluetooth: bpa10x: Use separate h4_recv_buf helper"). I wasn't able to find any explanation for duplicating the code in the discussion: https://lore.kernel.org/all/20180320181855.37297-1-marcel@holtmann.org/ https://lore.kernel.org/all/20180324091954.73229-2-marcel@holtmann.org/ Unfortunately, in the years since, several other drivers have come to also rely on this duplicated function, probably by accident. This is, at the very least, *extremely* confusing. It's also caused real issues when it's become out-of-sync, see the following: ef564119ba83 ("Bluetooth: hci_h4: Add support for ISO packets") 61b27cdf025b ("Bluetooth: hci_h4: Add support for ISO packets in h4_recv.h") This is the full diff between the two implementations today: --- orig.c +++ copy.c @@ -1,117 +1,100 @@ { - struct hci_uart *hu = hci_get_drvdata(hdev); - u8 alignment = hu->alignment ? hu->alignment : 1; - /* Check for error from previous call */ if (IS_ERR(skb)) skb = NULL; while (count) { int i, len; - /* remove padding bytes from buffer */ - for (; hu->padding && count > 0; hu->padding--) { - count--; - buffer++; - } - if (!count) - break; - if (!skb) { for (i = 0; i < pkts_count; i++) { if (buffer[0] != (&pkts[i])->type) continue; skb = bt_skb_alloc((&pkts[i])->maxlen, GFP_ATOMIC); if (!skb) return ERR_PTR(-ENOMEM); hci_skb_pkt_type(skb) = (&pkts[i])->type; hci_skb_expect(skb) = (&pkts[i])->hlen; break; } /* Check for invalid packet type */ if (!skb) return ERR_PTR(-EILSEQ); count -= 1; buffer += 1; } len = min_t(uint, hci_skb_expect(skb) - skb->len, count); skb_put_data(skb, buffer, len); count -= len; buffer += len; /* Check for partial packet */ if (skb->len < hci_skb_expect(skb)) continue; for (i = 0; i < pkts_count; i++) { if (hci_skb_pkt_type(skb) == (&pkts[i])->type) break; } if (i >= pkts_count) { kfree_skb(skb); return ERR_PTR(-EILSEQ); } if (skb->len == (&pkts[i])->hlen) { u16 dlen; switch ((&pkts[i])->lsize) { case 0: /* No variable data length */ dlen = 0; break; case 1: /* Single octet variable length */ dlen = skb->data[(&pkts[i])->loff]; hci_skb_expect(skb) += dlen; if (skb_tailroom(skb) < dlen) { kfree_skb(skb); return ERR_PTR(-EMSGSIZE); } break; case 2: /* Double octet variable length */ dlen = get_unaligned_le16(skb->data + (&pkts[i])->loff); hci_skb_expect(skb) += dlen; if (skb_tailroom(skb) < dlen) { kfree_skb(skb); return ERR_PTR(-EMSGSIZE); } break; default: /* Unsupported variable length */ kfree_skb(skb); return ERR_PTR(-EILSEQ); } if (!dlen) { - hu->padding = (skb->len + 1) % alignment; - hu->padding = (alignment - hu->padding) % alignment; - /* No more data, complete frame */ (&pkts[i])->recv(hdev, skb); skb = NULL; } } else { - hu->padding = (skb->len + 1) % alignment; - hu->padding = (alignment - hu->padding) % alignment; - /* Complete frame */ (&pkts[i])->recv(hdev, skb); skb = NULL; } } return skb; } -EXPORT_SYMBOL_GPL(h4_recv_buf) As I read this: If alignment is one, and padding is zero, padding remains zero throughout the loop. So it seems to me that the two functions behave strictly identically in that case. All the duplicated defines are also identical, as is the duplicated h4_recv_pkt structure declaration. All four drivers which use the duplicated function use the default alignment of one, and the default padding of zero. I therefore conclude the duplicate function may be safely replaced with the core one. I raised this in an RFC a few months ago, and didn't get much interest: https://lore.kernel.org/all/CABBYNZ+ONkYtq2fR-8PtL3X-vetvJ0BdP4MTw9cNpjLDzG3HUQ@mail.gmail.com/ ...but I'm still wary I've missed something, and I'd really appreciate more eyeballs on it. I tested this successfully on btnxpuart a few months ago, but unfortunately I no longer have access to that hardware. Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Calvin Owens <calvin@wbinvd.org> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-08-25 21:11:08 -07:00
treewide, serdev: change receive_buf() return type to size_t receive_buf() is called from ttyport_receive_buf() that expects values ">= 0" from serdev_controller_receive_buf(), change its return type from ssize_t to size_t. The need for this clean-up was noticed while fixing a warning, see commit 94d053942544 ("Bluetooth: btnxpuart: fix recv_buf() return value"). Changing the callback prototype to return an unsigned seems the best way to document the API and ensure that is properly used. GNSS drivers implementation of serdev receive_buf() callback return directly the return value of gnss_insert_raw(). gnss_insert_raw() returns a signed int, however this is not an issue since the value returned is always positive, because of the kfifo_in() implementation. gnss_insert_raw() could be changed to return also an unsigned, however this is not implemented here as request by the GNSS maintainer Johan Hovold. Suggested-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/ Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio Reviewed-by: Johan Hovold <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Alex Elder <elder@linaro.org> Acked-by: Maximilian Luz <luzmaximilian@gmail.com> # for platform/surface Acked-by: Lee Jones <lee@kernel.org> Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240122180551.34429-1-francesco@dolcini.it Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-22 19:05:51 +01:00
2019-03-05 08:14:25 +08:00