From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- drivers/mtd/tests/readtest.c | 215 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 drivers/mtd/tests/readtest.c (limited to 'drivers/mtd/tests/readtest.c') diff --git a/drivers/mtd/tests/readtest.c b/drivers/mtd/tests/readtest.c new file mode 100644 index 000000000..99670ef91 --- /dev/null +++ b/drivers/mtd/tests/readtest.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2006-2008 Nokia Corporation + * + * Check MTD device read. + * + * Author: Adrian Hunter + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include + +#include "mtd_test.h" + +static int dev = -EINVAL; +module_param(dev, int, S_IRUGO); +MODULE_PARM_DESC(dev, "MTD device number to use"); + +static struct mtd_info *mtd; +static unsigned char *iobuf; +static unsigned char *iobuf1; +static unsigned char *bbt; + +static int pgsize; +static int ebcnt; +static int pgcnt; + +static int read_eraseblock_by_page(int ebnum) +{ + int i, ret, err = 0; + loff_t addr = (loff_t)ebnum * mtd->erasesize; + void *buf = iobuf; + void *oobbuf = iobuf1; + + for (i = 0; i < pgcnt; i++) { + memset(buf, 0 , pgsize); + ret = mtdtest_read(mtd, addr, pgsize, buf); + if (ret) { + if (!err) + err = ret; + } + if (mtd->oobsize) { + struct mtd_oob_ops ops = { }; + + ops.mode = MTD_OPS_PLACE_OOB; + ops.len = 0; + ops.retlen = 0; + ops.ooblen = mtd->oobsize; + ops.oobretlen = 0; + ops.ooboffs = 0; + ops.datbuf = NULL; + ops.oobbuf = oobbuf; + ret = mtd_read_oob(mtd, addr, &ops); + if ((ret && !mtd_is_bitflip(ret)) || + ops.oobretlen != mtd->oobsize) { + pr_err("error: read oob failed at " + "%#llx\n", (long long)addr); + if (!err) + err = ret; + if (!err) + err = -EINVAL; + } + oobbuf += mtd->oobsize; + } + addr += pgsize; + buf += pgsize; + } + + return err; +} + +static void dump_eraseblock(int ebnum) +{ + int i, j, n; + char line[128]; + int pg, oob; + + pr_info("dumping eraseblock %d\n", ebnum); + n = mtd->erasesize; + for (i = 0; i < n;) { + char *p = line; + + p += sprintf(p, "%05x: ", i); + for (j = 0; j < 32 && i < n; j++, i++) + p += sprintf(p, "%02x", (unsigned int)iobuf[i]); + printk(KERN_CRIT "%s\n", line); + cond_resched(); + } + if (!mtd->oobsize) + return; + pr_info("dumping oob from eraseblock %d\n", ebnum); + n = mtd->oobsize; + for (pg = 0, i = 0; pg < pgcnt; pg++) + for (oob = 0; oob < n;) { + char *p = line; + + p += sprintf(p, "%05x: ", i); + for (j = 0; j < 32 && oob < n; j++, oob++, i++) + p += sprintf(p, "%02x", + (unsigned int)iobuf1[i]); + printk(KERN_CRIT "%s\n", line); + cond_resched(); + } +} + +static int __init mtd_readtest_init(void) +{ + uint64_t tmp; + int err, i; + + printk(KERN_INFO "\n"); + printk(KERN_INFO "=================================================\n"); + + if (dev < 0) { + pr_info("Please specify a valid mtd-device via module parameter\n"); + return -EINVAL; + } + + pr_info("MTD device: %d\n", dev); + + mtd = get_mtd_device(NULL, dev); + if (IS_ERR(mtd)) { + err = PTR_ERR(mtd); + pr_err("error: Cannot get MTD device\n"); + return err; + } + + if (mtd->writesize == 1) { + pr_info("not NAND flash, assume page size is 512 " + "bytes.\n"); + pgsize = 512; + } else + pgsize = mtd->writesize; + + tmp = mtd->size; + do_div(tmp, mtd->erasesize); + ebcnt = tmp; + pgcnt = mtd->erasesize / pgsize; + + pr_info("MTD device size %llu, eraseblock size %u, " + "page size %u, count of eraseblocks %u, pages per " + "eraseblock %u, OOB size %u\n", + (unsigned long long)mtd->size, mtd->erasesize, + pgsize, ebcnt, pgcnt, mtd->oobsize); + + err = -ENOMEM; + iobuf = kmalloc(mtd->erasesize, GFP_KERNEL); + if (!iobuf) + goto out; + iobuf1 = kmalloc(mtd->erasesize, GFP_KERNEL); + if (!iobuf1) + goto out; + + bbt = kzalloc(ebcnt, GFP_KERNEL); + if (!bbt) + goto out; + err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt); + if (err) + goto out; + + /* Read all eraseblocks 1 page at a time */ + pr_info("testing page read\n"); + for (i = 0; i < ebcnt; ++i) { + int ret; + + if (bbt[i]) + continue; + ret = read_eraseblock_by_page(i); + if (ret) { + dump_eraseblock(i); + if (!err) + err = ret; + } + + ret = mtdtest_relax(); + if (ret) { + err = ret; + goto out; + } + } + + if (err) + pr_info("finished with errors\n"); + else + pr_info("finished\n"); + +out: + + kfree(iobuf); + kfree(iobuf1); + kfree(bbt); + put_mtd_device(mtd); + if (err) + pr_info("error %d occurred\n", err); + printk(KERN_INFO "=================================================\n"); + return err; +} +module_init(mtd_readtest_init); + +static void __exit mtd_readtest_exit(void) +{ + return; +} +module_exit(mtd_readtest_exit); + +MODULE_DESCRIPTION("Read test module"); +MODULE_AUTHOR("Adrian Hunter"); +MODULE_LICENSE("GPL"); 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