On Sun, 2021-10-24 at 18:38 -0300, Gaston Gonzalez wrote:

Quoted strings should not be split across lines. As put it in [1]:
"never break user-visible strings such as printk messages because that
breaks the ability to grep for them."

While at it, fix the alignment of the arguments in the sentence.

Note: this introduce a checkpatch CHECK: line length of 123 exceeds 100
columns, as the line now is:

 vchiq_loud_error("%d: service %d (%c%c%c%c) version mismatch - local (%d, min %d) vs. remote (%d, min %d)",

But now the string is grep-able and the whole function call more
clear.

IMO: All of these should be changed

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h:#define VCHIQ_LOG_PREFIX   KERN_INFO "vchiq: "
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#ifndef vchiq_log_error
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#define vchiq_log_error(cat, fmt, ...) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h- do { if (cat >= VCHIQ_LOG_ERROR) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h:         printk(VCHIQ_LOG_PREFIX fmt "\n", ##__VA_ARGS__); } while (0)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#endif
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#ifndef vchiq_log_warning
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#define vchiq_log_warning(cat, fmt, ...) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h- do { if (cat >= VCHIQ_LOG_WARNING) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h:          printk(VCHIQ_LOG_PREFIX fmt "\n", ##__VA_ARGS__); } while (0)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#endif
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#ifndef vchiq_log_info
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#define vchiq_log_info(cat, fmt, ...) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h- do { if (cat >= VCHIQ_LOG_INFO) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h:         printk(VCHIQ_LOG_PREFIX fmt "\n", ##__VA_ARGS__); } while (0)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#endif
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#ifndef vchiq_log_trace
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#define vchiq_log_trace(cat, fmt, ...) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h- do { if (cat >= VCHIQ_LOG_TRACE) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h:         printk(VCHIQ_LOG_PREFIX fmt "\n", ##__VA_ARGS__); } while (0)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#endif
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-#define vchiq_loud_error(...) \
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h- vchiq_log_error(vchiq_core_log_level, "===== " __VA_ARGS__)
drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h-

I suggest using the rather more common vchiq_err, vchiq_warn, vchiq_info
and if necessary vchiq_trace.  Also the cat >= test is unnecessary and
this should just use the more common standard logging facilities.

vchiq_loud_error is IMO unnecessary.

Also several of the uses of these macros already have '\n' terminations
so that just adds unnecessary blank lines in the logging.