Re: [PATCH] media: s5p-jpeg: change "RST" to "RSET" to fix build warnings

On 9/5/21 11:51 PM, Mauro Carvalho Chehab wrote:

Em Sun,  5 Sep 2021 16:57:15 -0700
Randy Dunlap [off-list ref] escreveu:

quoted

The use of a macro named 'RST' conflicts with one of the same name
in arch/mips/include/asm/mach-rc32434/rb.h. This causes build
warnings on some MIPS builds.

Change the use of RST to the name RSET.

Fixes these build warnings:

In file included from ../drivers/media/platform/s5p-jpeg/jpeg-hw-exynos3250.c:14:
../drivers/media/platform/s5p-jpeg/jpeg-core.h:43: warning: "RST" redefined
    43 | #define RST                             0xd0
       |
../arch/mips/include/asm/mach-rc32434/rb.h:13: note: this is the location of the previous definition
    13 | #define RST             (1 << 15)

In file included from ../drivers/media/platform/s5p-jpeg/jpeg-hw-s5p.c:13:
../drivers/media/platform/s5p-jpeg/jpeg-core.h:43: warning: "RST" redefined
    43 | #define RST                             0xd0
../arch/mips/include/asm/mach-rc32434/rb.h:13: note: this is the location of the previous definition
    13 | #define RST             (1 << 15)

In file included from ../drivers/media/platform/s5p-jpeg/jpeg-hw-exynos4.c:12:
../drivers/media/platform/s5p-jpeg/jpeg-core.h:43: warning: "RST" redefined
    43 | #define RST                             0xd0
../arch/mips/include/asm/mach-rc32434/rb.h:13: note: this is the location of the previous definition
    13 | #define RST             (1 << 15)

In file included from ../drivers/media/platform/s5p-jpeg/jpeg-core.c:31:
../drivers/media/platform/s5p-jpeg/jpeg-core.h:43: warning: "RST" redefined
    43 | #define RST                             0xd0
../arch/mips/include/asm/mach-rc32434/rb.h:13: note: this is the location of the previous definition
    13 | #define RST             (1 << 15)

Fixes: bb677f3ac434 ("[media] Exynos4 JPEG codec v4l2 driver")
Reported-by: kernel test robot <redacted>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Cc: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: linux-arm-kernel@lists.infradead.org
---
  drivers/media/platform/s5p-jpeg/jpeg-core.c |    2 +-
  drivers/media/platform/s5p-jpeg/jpeg-core.h |    2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)

--- linux-next-20210903.orig/drivers/media/platform/s5p-jpeg/jpeg-core.c
+++ linux-next-20210903/drivers/media/platform/s5p-jpeg/jpeg-core.c

@@ -1203,7 +1203,7 @@ static bool s5p_jpeg_parse_hdr(struct s5
  			break;
  
  		/* skip payload-less markers */
-		case RST ... RST + 7:
+		case RSET ... RSET + 7:
  		case SOI:
  		case EOI:
  		case TEM:
--- linux-next-20210903.orig/drivers/media/platform/s5p-jpeg/jpeg-core.h
+++ linux-next-20210903/drivers/media/platform/s5p-jpeg/jpeg-core.h

@@ -40,7 +40,7 @@
  #define TEM				0x01
  #define SOF0				0xc0
  #define DHT				0xc4
-#define RST				0xd0
+#define RSET				0xd0
  #define SOI				0xd8
  #define EOI				0xd9
  #define	SOS				0xda

I don't like this change, for a couple reasons:

1. the JPEG marker is "RST" (actually, "RST0") instead of "RSET"
    (see pag. 36 https://www.w3.org/Graphics/JPEG/itu-t81.pdf). The
    close it sticks with the JPEG standard, the better;

It looks like RST0 would work fine here.
[builds] Yes, it does.

2. better to add a namespace here, as other JPEG markers like SOS,
    SOI and EOI seems to have a high chance of happening somewhere
    else on other kernel headers in the future.

Makes sense.

So, IMO, the best would be to rename all those markers as a hole, with
something similar to:

	$ for i in TEM SOF0 DHT RST SOI EOI SOS DQT DHP; do sed "s,\b$i\b,JPEG_MARKER_$i,g" -i drivers/media/platform/s5p-jpeg/*.[ch]; done

and manually adjust the patch, as at least this hunk could be
improved:

	@@ -187,11 +187,11 @@ struct s5p_jpeg_marker {
	  * @fmt:       driver-specific format of this queue
	  * @w:         image width
	  * @h:         image height
	- * @sos:       SOS marker's position relative to the buffer beginning
	- * @dht:       DHT markers' positions relative to the buffer beginning
	- * @dqt:       DQT markers' positions relative to the buffer beginning
	- * @sof:       SOF0 marker's position relative to the buffer beginning
	- * @sof_len:   SOF0 marker's payload length (without length field itself)
	+ * @sos:       JPEG_MARKER_SOS marker's position relative to the buffer beginning
	+ * @dht:       JPEG_MARKER_DHT markers' positions relative to the buffer beginning
	+ * @dqt:       JPEG_MARKER_DQT markers' positions relative to the buffer beginning
	+ * @sof:       JPEG_MARKER_SOF0 marker's position relative to the buffer beginning
	+ * @sof_len:   JPEG_MARKER_SOF0 marker's payload length (without length field itself)
	  * @size:      image buffer size in bytes
	  */

to avoid repeating the word marker.

OK, I can do that.

thanks.

-- 
~Randy


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