From: Yifeng Li tomli@tomli.me
commit 4ed7d2ccb7684510ec5f7a8f7ef534bc6a3d55b2 upstream.
Loongson MIPS netbooks use 1024x600 LCD panels, which is the original target platform of this driver, but nearly all old x86 laptops have 1024x768. Lighting 768 panels using 600's timings would partially garble the display. Since it's not possible to distinguish them reliably, we change the default to 768, but keep 600 as-is on MIPS.
Further, earlier laptops, such as IBM Thinkpad 240X, has a 800x600 LCD panel, this driver would probably garbled those display. As we don't have one for testing, the original behavior of the driver is kept as-is, but the problem has been documented is the comments.
Signed-off-by: Yifeng Li tomli@tomli.me Tested-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Cc: Teddy Wang teddy.wang@siliconmotion.com Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/video/fbdev/sm712.h | 7 +++-- drivers/video/fbdev/sm712fb.c | 53 +++++++++++++++++++++++++++++++----------- 2 files changed, 44 insertions(+), 16 deletions(-)
--- a/drivers/video/fbdev/sm712.h +++ b/drivers/video/fbdev/sm712.h @@ -15,9 +15,10 @@
#define FB_ACCEL_SMI_LYNX 88
-#define SCREEN_X_RES 1024 -#define SCREEN_Y_RES 600 -#define SCREEN_BPP 16 +#define SCREEN_X_RES 1024 +#define SCREEN_Y_RES_PC 768 +#define SCREEN_Y_RES_NETBOOK 600 +#define SCREEN_BPP 16
#define dac_reg (0x3c8) #define dac_val (0x3c9) --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -1463,6 +1463,43 @@ static u_long sm7xx_vram_probe(struct sm return 0; /* unknown hardware */ }
+static void sm7xx_resolution_probe(struct smtcfb_info *sfb) +{ + /* get mode parameter from smtc_scr_info */ + if (smtc_scr_info.lfb_width != 0) { + sfb->fb->var.xres = smtc_scr_info.lfb_width; + sfb->fb->var.yres = smtc_scr_info.lfb_height; + sfb->fb->var.bits_per_pixel = smtc_scr_info.lfb_depth; + goto final; + } + + /* + * No parameter, default resolution is 1024x768-16. + * + * FIXME: earlier laptops, such as IBM Thinkpad 240X, has a 800x600 + * panel, also see the comments about Thinkpad 240X above. + */ + sfb->fb->var.xres = SCREEN_X_RES; + sfb->fb->var.yres = SCREEN_Y_RES_PC; + sfb->fb->var.bits_per_pixel = SCREEN_BPP; + +#ifdef CONFIG_MIPS + /* + * Loongson MIPS netbooks use 1024x600 LCD panels, which is the original + * target platform of this driver, but nearly all old x86 laptops have + * 1024x768. Lighting 768 panels using 600's timings would partially + * garble the display, so we don't want that. But it's not possible to + * distinguish them reliably. + * + * So we change the default to 768, but keep 600 as-is on MIPS. + */ + sfb->fb->var.yres = SCREEN_Y_RES_NETBOOK; +#endif + +final: + big_pixel_depth(sfb->fb->var.bits_per_pixel, smtc_scr_info.lfb_depth); +} + static int smtcfb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { @@ -1508,19 +1545,6 @@ static int smtcfb_pci_probe(struct pci_d
sm7xx_init_hw();
- /* get mode parameter from smtc_scr_info */ - if (smtc_scr_info.lfb_width != 0) { - sfb->fb->var.xres = smtc_scr_info.lfb_width; - sfb->fb->var.yres = smtc_scr_info.lfb_height; - sfb->fb->var.bits_per_pixel = smtc_scr_info.lfb_depth; - } else { - /* default resolution 1024x600 16bit mode */ - sfb->fb->var.xres = SCREEN_X_RES; - sfb->fb->var.yres = SCREEN_Y_RES; - sfb->fb->var.bits_per_pixel = SCREEN_BPP; - } - - big_pixel_depth(sfb->fb->var.bits_per_pixel, smtc_scr_info.lfb_depth); /* Map address and memory detection */ mmio_base = pci_resource_start(pdev, 0); pci_read_config_byte(pdev, PCI_REVISION_ID, &sfb->chip_rev_id); @@ -1582,6 +1606,9 @@ static int smtcfb_pci_probe(struct pci_d goto failed_fb; }
+ /* probe and decide resolution */ + sm7xx_resolution_probe(sfb); + /* can support 32 bpp */ if (sfb->fb->var.bits_per_pixel == 15) sfb->fb->var.bits_per_pixel = 16;