From 2d8afda40e31b23d2981fe273d32b01b9c87b6d9 Mon Sep 17 00:00:00 2001 From: Krishna Kurapati Date: Sat, 27 Aug 2022 08:45:10 +0530 Subject: [PATCH] UPSTREAM: usb: gadget: mass_storage: Fix cdrom data transfers on MAC-OS During cdrom emulation, the response to read_toc command must contain the cdrom address as the number of sectors (2048 byte sized blocks) represented either as an absolute value (when MSF bit is '0') or in terms of PMin/PSec/PFrame (when MSF bit is set to '1'). Incase of cdrom, the fsg_lun_open call sets the sector size to 2048 bytes. When MAC OS sends a read_toc request with MSF set to '1', the store_cdrom_address assumes that the address being provided is the LUN size represented in 512 byte sized blocks instead of 2048. It tries to modify the address further to convert it to 2048 byte sized blocks and store it in MSF format. This results in data transfer failures as the cdrom address being provided in the read_toc response is incorrect. Fixes: 3f565a363cee ("usb: gadget: storage: adapt logic block size to bound block devices") Cc: stable@vger.kernel.org Acked-by: Alan Stern Signed-off-by: Krishna Kurapati Link: https://lore.kernel.org/r/1661570110-19127-1-git-send-email-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 9d4dc16ec71bd6368548e9743223e449b4377fc7) Bug: 245221519 Change-Id: I50687e4dfc2b26d35adce50e51b54d28fb85967e Signed-off-by: Krishna Kurapati --- drivers/usb/gadget/function/storage_common.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c index 2451e45ada6e..87bfe87daa86 100644 --- a/drivers/usb/gadget/function/storage_common.c +++ b/drivers/usb/gadget/function/storage_common.c @@ -294,8 +294,10 @@ EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub); void store_cdrom_address(u8 *dest, int msf, u32 addr) { if (msf) { - /* Convert to Minutes-Seconds-Frames */ - addr >>= 2; /* Convert to 2048-byte frames */ + /* + * Convert to Minutes-Seconds-Frames. + * Sector size is already set to 2048 bytes. + */ addr += 2*75; /* Lead-in occupies 2 seconds */ dest[3] = addr % 75; /* Frames */ addr /= 75;