Revision 29664923725a384dc7e0f74af7c66e5ab7bb2a26 authored by Marco Giunta on 18 October 2021, 16:25:52 UTC, committed by Takashi Iwai on 19 October 2021, 06:07:01 UTC
When a Jieli Technology USB Webcam is connected, the video part works well, but the mic sound is speeded up. On dmesg there are messages about different rates from the runtime rates, warnings about volume resolution and lastly, the log is filled, every 5 seconds, with retire_capture_urb error messages. The mic works only when ep packet size is set to wMaxPacketSize (normal sound and no more retire_capture_urb error messages). Skipping reading sample rate, fixes the messages about different rates and forcing a volume resolution, fixes warnings about volume range. I have arbitrarily choosed the value (16): I read in a comment that there should be no more than 255 levels, so 4096 (max volume) / 16 = 0-255. Signed-off-by: Marco Giunta <giun7a@gmail.com> Link: https://lore.kernel.org/r/20211018162552.12082-1-giun7a@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
1 parent eadeb06
checksum.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* IP/TCP/UDP checksumming routines
*
* Authors: Jorge Cwik, <jorge@laser.satlink.net>
* Arnt Gulbrandsen, <agulbra@nvg.unit.no>
* Tom May, <ftom@netcom.com>
* Andreas Schwab, <schwab@issan.informatik.uni-dortmund.de>
* Lots of code moved from tcp.c and ip.c; see those files
* for more names.
*
* 03/02/96 Jes Sorensen, Andreas Schwab, Roman Hodek:
* Fixed some nasty bugs, causing some horrible crashes.
* A: At some points, the sum (%0) was used as
* length-counter instead of the length counter
* (%1). Thanks to Roman Hodek for pointing this out.
* B: GCC seems to mess up if one uses too many
* data-registers to hold input values and one tries to
* specify d0 and d1 as scratch registers. Letting gcc
* choose these registers itself solves the problem.
*/
/* Revised by Kenneth Albanowski for m68knommu. Basic problem: unaligned access
kills, so most of the assembly has to go. */
#include <linux/export.h>
#include <net/checksum.h>
#include <asm/byteorder.h>
#ifndef do_csum
static inline unsigned short from32to16(unsigned int x)
{
/* add up 16-bit and 16-bit for 16+c bit */
x = (x & 0xffff) + (x >> 16);
/* add up carry.. */
x = (x & 0xffff) + (x >> 16);
return x;
}
static unsigned int do_csum(const unsigned char *buff, int len)
{
int odd;
unsigned int result = 0;
if (len <= 0)
goto out;
odd = 1 & (unsigned long) buff;
if (odd) {
#ifdef __LITTLE_ENDIAN
result += (*buff << 8);
#else
result = *buff;
#endif
len--;
buff++;
}
if (len >= 2) {
if (2 & (unsigned long) buff) {
result += *(unsigned short *) buff;
len -= 2;
buff += 2;
}
if (len >= 4) {
const unsigned char *end = buff + ((unsigned)len & ~3);
unsigned int carry = 0;
do {
unsigned int w = *(unsigned int *) buff;
buff += 4;
result += carry;
result += w;
carry = (w > result);
} while (buff < end);
result += carry;
result = (result & 0xffff) + (result >> 16);
}
if (len & 2) {
result += *(unsigned short *) buff;
buff += 2;
}
}
if (len & 1)
#ifdef __LITTLE_ENDIAN
result += *buff;
#else
result += (*buff << 8);
#endif
result = from32to16(result);
if (odd)
result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
out:
return result;
}
#endif
#ifndef ip_fast_csum
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*/
__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
return (__force __sum16)~do_csum(iph, ihl*4);
}
EXPORT_SYMBOL(ip_fast_csum);
#endif
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* returns a 32-bit number suitable for feeding into itself
* or csum_tcpudp_magic
*
* this function must be called with even lengths, except
* for the last fragment, which may be odd
*
* it's best to have buff aligned on a 32-bit boundary
*/
__wsum csum_partial(const void *buff, int len, __wsum wsum)
{
unsigned int sum = (__force unsigned int)wsum;
unsigned int result = do_csum(buff, len);
/* add in old sum, and carry.. */
result += sum;
if (sum > result)
result += 1;
return (__force __wsum)result;
}
EXPORT_SYMBOL(csum_partial);
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
__sum16 ip_compute_csum(const void *buff, int len)
{
return (__force __sum16)~do_csum(buff, len);
}
EXPORT_SYMBOL(ip_compute_csum);
#ifndef csum_tcpudp_nofold
static inline u32 from64to32(u64 x)
{
/* add up 32-bit and 32-bit for 32+c bit */
x = (x & 0xffffffff) + (x >> 32);
/* add up carry.. */
x = (x & 0xffffffff) + (x >> 32);
return (u32)x;
}
__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto, __wsum sum)
{
unsigned long long s = (__force u32)sum;
s += (__force u32)saddr;
s += (__force u32)daddr;
#ifdef __BIG_ENDIAN
s += proto + len;
#else
s += (proto + len) << 8;
#endif
return (__force __wsum)from64to32(s);
}
EXPORT_SYMBOL(csum_tcpudp_nofold);
#endif
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