queue-4.4/fbdev-sm712fb-use-1024x768-by-default-on-non-mips-fix-garbled-display.patch

   1 From 4ed7d2ccb7684510ec5f7a8f7ef534bc6a3d55b2 Mon Sep 17 00:00:00 2001
   2 From: Yifeng Li <tomli@tomli.me>
   3 Date: Mon, 1 Apr 2019 17:46:59 +0200
   4 Subject: fbdev: sm712fb: use 1024x768 by default on non-MIPS, fix garbled display
   5
   6 From: Yifeng Li <tomli@tomli.me>
   7
   8 commit 4ed7d2ccb7684510ec5f7a8f7ef534bc6a3d55b2 upstream.
   9
  10 Loongson MIPS netbooks use 1024x600 LCD panels, which is the original
  11 target platform of this driver, but nearly all old x86 laptops have
  12 1024x768. Lighting 768 panels using 600's timings would partially
  13 garble the display. Since it's not possible to distinguish them reliably,
  14 we change the default to 768, but keep 600 as-is on MIPS.
  15
  16 Further, earlier laptops, such as IBM Thinkpad 240X, has a 800x600 LCD
  17 panel, this driver would probably garbled those display. As we don't
  18 have one for testing, the original behavior of the driver is kept as-is,
  19 but the problem has been documented is the comments.
  20
  21 Signed-off-by: Yifeng Li <tomli@tomli.me>
  22 Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
  23 Cc: Teddy Wang <teddy.wang@siliconmotion.com>
  24 Cc: <stable@vger.kernel.org>  # v4.4+
  25 Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27
  28 ---
  29  drivers/video/fbdev/sm712.h   |    7 +++--
  30  drivers/video/fbdev/sm712fb.c |   53 +++++++++++++++++++++++++++++++-----------
  31  2 files changed, 44 insertions(+), 16 deletions(-)
  32
  33 --- a/drivers/video/fbdev/sm712.h
  34 +++ b/drivers/video/fbdev/sm712.h
  35 @@ -15,9 +15,10 @@
  36
  37  #define FB_ACCEL_SMI_LYNX 88
  38
  39 -#define SCREEN_X_RES      1024
  40 -#define SCREEN_Y_RES      600
  41 -#define SCREEN_BPP        16
  42 +#define SCREEN_X_RES          1024
  43 +#define SCREEN_Y_RES_PC       768
  44 +#define SCREEN_Y_RES_NETBOOK  600
  45 +#define SCREEN_BPP            16
  46
  47  #define dac_reg        (0x3c8)
  48  #define dac_val        (0x3c9)
  49 --- a/drivers/video/fbdev/sm712fb.c
  50 +++ b/drivers/video/fbdev/sm712fb.c
  51 @@ -1462,6 +1462,43 @@ static u_long sm7xx_vram_probe(struct sm
  52         return 0;  /* unknown hardware */
  53  }
  54
  55 +static void sm7xx_resolution_probe(struct smtcfb_info *sfb)
  56 +{
  57 +       /* get mode parameter from smtc_scr_info */
  58 +       if (smtc_scr_info.lfb_width != 0) {
  59 +               sfb->fb->var.xres = smtc_scr_info.lfb_width;
  60 +               sfb->fb->var.yres = smtc_scr_info.lfb_height;
  61 +               sfb->fb->var.bits_per_pixel = smtc_scr_info.lfb_depth;
  62 +               goto final;
  63 +       }
  64 +
  65 +       /*
  66 +        * No parameter, default resolution is 1024x768-16.
  67 +        *
  68 +        * FIXME: earlier laptops, such as IBM Thinkpad 240X, has a 800x600
  69 +        * panel, also see the comments about Thinkpad 240X above.
  70 +        */
  71 +       sfb->fb->var.xres = SCREEN_X_RES;
  72 +       sfb->fb->var.yres = SCREEN_Y_RES_PC;
  73 +       sfb->fb->var.bits_per_pixel = SCREEN_BPP;
  74 +
  75 +#ifdef CONFIG_MIPS
  76 +       /*
  77 +        * Loongson MIPS netbooks use 1024x600 LCD panels, which is the original
  78 +        * target platform of this driver, but nearly all old x86 laptops have
  79 +        * 1024x768. Lighting 768 panels using 600's timings would partially
  80 +        * garble the display, so we don't want that. But it's not possible to
  81 +        * distinguish them reliably.
  82 +        *
  83 +        * So we change the default to 768, but keep 600 as-is on MIPS.
  84 +        */
  85 +       sfb->fb->var.yres = SCREEN_Y_RES_NETBOOK;
  86 +#endif
  87 +
  88 +final:
  89 +       big_pixel_depth(sfb->fb->var.bits_per_pixel, smtc_scr_info.lfb_depth);
  90 +}
  91 +
  92  static int smtcfb_pci_probe(struct pci_dev *pdev,
  93                             const struct pci_device_id *ent)
  94  {
  95 @@ -1507,19 +1544,6 @@ static int smtcfb_pci_probe(struct pci_d
  96
  97         sm7xx_init_hw();
  98
  99 -       /* get mode parameter from smtc_scr_info */
 100 -       if (smtc_scr_info.lfb_width != 0) {
 101 -               sfb->fb->var.xres = smtc_scr_info.lfb_width;
 102 -               sfb->fb->var.yres = smtc_scr_info.lfb_height;
 103 -               sfb->fb->var.bits_per_pixel = smtc_scr_info.lfb_depth;
 104 -       } else {
 105 -               /* default resolution 1024x600 16bit mode */
 106 -               sfb->fb->var.xres = SCREEN_X_RES;
 107 -               sfb->fb->var.yres = SCREEN_Y_RES;
 108 -               sfb->fb->var.bits_per_pixel = SCREEN_BPP;
 109 -       }
 110 -
 111 -       big_pixel_depth(sfb->fb->var.bits_per_pixel, smtc_scr_info.lfb_depth);
 112         /* Map address and memory detection */
 113         mmio_base = pci_resource_start(pdev, 0);
 114         pci_read_config_byte(pdev, PCI_REVISION_ID, &sfb->chip_rev_id);
 115 @@ -1581,6 +1605,9 @@ static int smtcfb_pci_probe(struct pci_d
 116                 goto failed_fb;
 117         }
 118
 119 +       /* probe and decide resolution */
 120 +       sm7xx_resolution_probe(sfb);
 121 +
 122         /* can support 32 bpp */
 123         if (15 == sfb->fb->var.bits_per_pixel)
 124                 sfb->fb->var.bits_per_pixel = 16;