From 76824d2467feb1828b745d6add2541918d7be3da Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Sat, 16 May 2026 14:53:45 +0300 Subject: [PATCH] drm/msm/snapshot: fix dumping of the unaligned regions The snapshotting code internally aligns data segment to 16 bytes. This works fine for DPU code (where most of the regions are aligned), but fails for snapshotting of the DSI data (because DSI data region is shifted by 4 bytes). Fix the code by removing length alignment and by accurately printing last registers in the region. While reworking the code also fix the 16x memory overallocation in msm_disp_state_dump_regs(). Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot") Reported-by: Salendarsingh Gaud Signed-off-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/725449/ Message-ID: <20260516-msm-fix-dsi-dump-2-v2-1-9e49fb2d240e@oss.qualcomm.com> Signed-off-by: Rob Clark --- .../gpu/drm/msm/disp/msm_disp_snapshot_util.c | 24 ++++++++++++++----- 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c index 636bcb65a2a4..01a7019f5d67 100644 --- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c +++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c @@ -9,7 +9,7 @@ #include "msm_disp_snapshot.h" -static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *base_addr) +static void msm_disp_state_dump_regs(u32 **reg, u32 len, void __iomem *base_addr) { u32 len_padded; u32 num_rows; @@ -19,11 +19,11 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b void __iomem *end_addr; int i; - len_padded = aligned_len * REG_DUMP_ALIGN; - num_rows = aligned_len / REG_DUMP_ALIGN; + len_padded = round_up(len, REG_DUMP_ALIGN); + num_rows = DIV_ROUND_UP(len, REG_DUMP_ALIGN); addr = base_addr; - end_addr = base_addr + aligned_len; + end_addr = base_addr + len; *reg = kvzalloc(len_padded, GFP_KERNEL); if (!*reg) @@ -48,8 +48,8 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b static void msm_disp_state_print_regs(const u32 *dump_addr, u32 len, void __iomem *base_addr, struct drm_printer *p) { + void __iomem *addr, *end_addr; int i; - void __iomem *addr; u32 num_rows; if (!dump_addr) { @@ -58,6 +58,7 @@ static void msm_disp_state_print_regs(const u32 *dump_addr, u32 len, } addr = base_addr; + end_addr = base_addr + len; num_rows = len / REG_DUMP_ALIGN; for (i = 0; i < num_rows; i++) { @@ -67,6 +68,17 @@ static void msm_disp_state_print_regs(const u32 *dump_addr, u32 len, dump_addr[i * 4 + 2], dump_addr[i * 4 + 3]); addr += REG_DUMP_ALIGN; } + + if (addr != end_addr) { + drm_printf(p, "0x%lx : %08x", + (unsigned long)(addr - base_addr), + dump_addr[i * 4]); + if (addr + 0x4 < end_addr) + drm_printf(p, " %08x", dump_addr[i * 4 + 1]); + if (addr + 0x8 < end_addr) + drm_printf(p, " %08x", dump_addr[i * 4 + 2]); + drm_printf(p, "\n"); + } } void msm_disp_state_print(struct msm_disp_state *state, struct drm_printer *p) @@ -185,7 +197,7 @@ void msm_disp_snapshot_add_block(struct msm_disp_state *disp_state, u32 len, va_end(va); INIT_LIST_HEAD(&new_blk->node); - new_blk->size = ALIGN(len, REG_DUMP_ALIGN); + new_blk->size = len; new_blk->base_addr = base_addr; msm_disp_state_dump_regs(&new_blk->state, new_blk->size, base_addr);